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Flot Reference |
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-------------- |
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Consider a call to the plot function: |
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var plot = $.plot(placeholder, data, options) |
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The placeholder is a jQuery object or DOM element or jQuery expression |
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that the plot will be put into. This placeholder needs to have its |
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width and height set as explained in the README (go read that now if |
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you haven't, it's short). The plot will modify some properties of the |
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placeholder so it's recommended you simply pass in a div that you |
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don't use for anything else. Make sure you check any fancy styling |
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you apply to the div, e.g. background images have been reported to be a |
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problem on IE 7. |
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The format of the data is documented below, as is the available |
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options. The "plot" object returned has some methods you can call. |
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These are documented separately below. |
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Note that in general Flot gives no guarantees if you change any of the |
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objects you pass in to the plot function or get out of it since |
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they're not necessarily deep-copied. |
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Data Format |
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----------- |
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The data is an array of data series: |
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[ series1, series2, ... ] |
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A series can either be raw data or an object with properties. The raw |
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data format is an array of points: |
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[ [x1, y1], [x2, y2], ... ] |
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E.g. |
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[ [1, 3], [2, 14.01], [3.5, 3.14] ] |
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Note that to simplify the internal logic in Flot both the x and y |
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values must be numbers (even if specifying time series, see below for |
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how to do this). This is a common problem because you might retrieve |
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data from the database and serialize them directly to JSON without |
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noticing the wrong type. If you're getting mysterious errors, double |
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check that you're inputting numbers and not strings. |
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If a null is specified as a point or if one of the coordinates is null |
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or couldn't be converted to a number, the point is ignored when |
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drawing. As a special case, a null value for lines is interpreted as a |
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line segment end, i.e. the points before and after the null value are |
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not connected. |
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Lines and points take two coordinates. For bars, you can specify a |
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third coordinate which is the bottom of the bar (defaults to 0). |
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The format of a single series object is as follows: |
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{ |
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color: color or number |
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data: rawdata |
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label: string |
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lines: specific lines options |
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bars: specific bars options |
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points: specific points options |
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xaxis: 1 or 2 |
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yaxis: 1 or 2 |
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clickable: boolean |
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hoverable: boolean |
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shadowSize: number |
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} |
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You don't have to specify any of them except the data, the rest are |
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options that will get default values. Typically you'd only specify |
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label and data, like this: |
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{ |
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label: "y = 3", |
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data: [[0, 3], [10, 3]] |
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} |
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The label is used for the legend, if you don't specify one, the series |
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will not show up in the legend. |
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If you don't specify color, the series will get a color from the |
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auto-generated colors. The color is either a CSS color specification |
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(like "rgb(255, 100, 123)") or an integer that specifies which of |
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auto-generated colors to select, e.g. 0 will get color no. 0, etc. |
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The latter is mostly useful if you let the user add and remove series, |
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in which case you can hard-code the color index to prevent the colors |
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from jumping around between the series. |
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The "xaxis" and "yaxis" options specify which axis to use, specify 2 |
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to get the secondary axis (x axis at top or y axis to the right). |
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E.g., you can use this to make a dual axis plot by specifying |
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{ yaxis: 2 } for one data series. |
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"clickable" and "hoverable" can be set to false to disable |
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interactivity for specific series if interactivity is turned on in |
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the plot, see below. |
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The rest of the options are all documented below as they are the same |
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as the default options passed in via the options parameter in the plot |
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commmand. When you specify them for a specific data series, they will |
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override the default options for the plot for that data series. |
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Here's a complete example of a simple data specification: |
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[ { label: "Foo", data: [ [10, 1], [17, -14], [30, 5] ] }, |
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{ label: "Bar", data: [ [11, 13], [19, 11], [30, -7] ] } ] |
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Plot Options |
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------------ |
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All options are completely optional. They are documented individually |
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below, to change them you just specify them in an object, e.g. |
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var options = { |
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series: { |
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lines: { show: true }, |
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points: { show: true } |
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} |
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}; |
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$.plot(placeholder, data, options); |
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Customizing the legend |
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====================== |
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legend: { |
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show: boolean |
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labelFormatter: null or (fn: string, series object -> string) |
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labelBoxBorderColor: color |
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noColumns: number |
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position: "ne" or "nw" or "se" or "sw" |
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margin: number of pixels or [x margin, y margin] |
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backgroundColor: null or color |
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backgroundOpacity: number between 0 and 1 |
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container: null or jQuery object/DOM element/jQuery expression |
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} |
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The legend is generated as a table with the data series labels and |
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small label boxes with the color of the series. If you want to format |
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the labels in some way, e.g. make them to links, you can pass in a |
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function for "labelFormatter". Here's an example that makes them |
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clickable: |
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labelFormatter: function(label, series) { |
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// series is the series object for the label |
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return '<a href="#' + label + '">' + label + '</a>'; |
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} |
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"noColumns" is the number of columns to divide the legend table into. |
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"position" specifies the overall placement of the legend within the |
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plot (top-right, top-left, etc.) and margin the distance to the plot |
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edge (this can be either a number or an array of two numbers like [x, |
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y]). "backgroundColor" and "backgroundOpacity" specifies the |
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background. The default is a partly transparent auto-detected |
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background. |
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If you want the legend to appear somewhere else in the DOM, you can |
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specify "container" as a jQuery object/expression to put the legend |
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table into. The "position" and "margin" etc. options will then be |
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ignored. Note that Flot will overwrite the contents of the container. |
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Customizing the axes |
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==================== |
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xaxis, yaxis, x2axis, y2axis: { |
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mode: null or "time" |
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min: null or number |
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max: null or number |
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autoscaleMargin: null or number |
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labelWidth: null or number |
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labelHeight: null or number |
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transform: null or fn: number -> number |
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inverseTransform: null or fn: number -> number |
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ticks: null or number or ticks array or (fn: range -> ticks array) |
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tickSize: number or array |
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minTickSize: number or array |
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tickFormatter: (fn: number, object -> string) or string |
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tickDecimals: null or number |
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} |
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All axes have the same kind of options. The "mode" option |
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determines how the data is interpreted, the default of null means as |
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decimal numbers. Use "time" for time series data, see the next section. |
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The options "min"/"max" are the precise minimum/maximum value on the |
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scale. If you don't specify either of them, a value will automatically |
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be chosen based on the minimum/maximum data values. |
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The "autoscaleMargin" is a bit esoteric: it's the fraction of margin |
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that the scaling algorithm will add to avoid that the outermost points |
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ends up on the grid border. Note that this margin is only applied |
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when a min or max value is not explicitly set. If a margin is |
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specified, the plot will furthermore extend the axis end-point to the |
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nearest whole tick. The default value is "null" for the x axis and |
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0.02 for the y axis which seems appropriate for most cases. |
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"labelWidth" and "labelHeight" specifies a fixed size of the tick |
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labels in pixels. They're useful in case you need to align several |
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plots. |
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"transform" and "inverseTransform" are callbacks you can put in to |
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change the way the data is drawn. You can design a function to |
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compress or expand certain parts of the axis non-linearly, e.g. |
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suppress weekends or compress far away points with a logarithm or some |
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other means. When Flot draws the plot, each value is first put through |
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the transform function. Here's an example, the x axis can be turned |
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into a natural logarithm axis with the following code: |
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xaxis: { |
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transform: function (v) { return Math.log(v); }, |
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inverseTransform: function (v) { return Math.exp(v); } |
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} |
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Note that for finding extrema, Flot assumes that the transform |
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function does not reorder values (monotonicity is assumed). |
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The inverseTransform is simply the inverse of the transform function |
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(so v == inverseTransform(transform(v)) for all relevant v). It is |
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required for converting from canvas coordinates to data coordinates, |
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e.g. for a mouse interaction where a certain pixel is clicked. If you |
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don't use any interactive features of Flot, you may not need it. |
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The rest of the options deal with the ticks. |
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If you don't specify any ticks, a tick generator algorithm will make |
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some for you. The algorithm has two passes. It first estimates how |
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many ticks would be reasonable and uses this number to compute a nice |
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round tick interval size. Then it generates the ticks. |
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You can specify how many ticks the algorithm aims for by setting |
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"ticks" to a number. The algorithm always tries to generate reasonably |
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round tick values so even if you ask for three ticks, you might get |
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five if that fits better with the rounding. If you don't want any |
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ticks at all, set "ticks" to 0 or an empty array. |
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Another option is to skip the rounding part and directly set the tick |
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interval size with "tickSize". If you set it to 2, you'll get ticks at |
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2, 4, 6, etc. Alternatively, you can specify that you just don't want |
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ticks at a size less than a specific tick size with "minTickSize". |
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Note that for time series, the format is an array like [2, "month"], |
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see the next section. |
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If you want to completely override the tick algorithm, you can specify |
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an array for "ticks", either like this: |
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ticks: [0, 1.2, 2.4] |
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Or like this where the labels are also customized: |
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ticks: [[0, "zero"], [1.2, "one mark"], [2.4, "two marks"]] |
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You can mix the two if you like. |
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For extra flexibility you can specify a function as the "ticks" |
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parameter. The function will be called with an object with the axis |
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min and max and should return a ticks array. Here's a simplistic tick |
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generator that spits out intervals of pi, suitable for use on the x |
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axis for trigonometric functions: |
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function piTickGenerator(axis) { |
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var res = [], i = Math.floor(axis.min / Math.PI); |
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do { |
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var v = i * Math.PI; |
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res.push([v, i + "\u03c0"]); |
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++i; |
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} while (v < axis.max); |
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return res; |
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} |
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You can control how the ticks look like with "tickDecimals", the |
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number of decimals to display (default is auto-detected). |
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Alternatively, for ultimate control over how ticks look like you can |
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provide a function to "tickFormatter". The function is passed two |
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parameters, the tick value and an "axis" object with information, and |
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should return a string. The default formatter looks like this: |
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function formatter(val, axis) { |
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return val.toFixed(axis.tickDecimals); |
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} |
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The axis object has "min" and "max" with the range of the axis, |
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"tickDecimals" with the number of decimals to round the value to and |
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"tickSize" with the size of the interval between ticks as calculated |
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by the automatic axis scaling algorithm (or specified by you). Here's |
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an example of a custom formatter: |
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function suffixFormatter(val, axis) { |
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if (val > 1000000) |
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return (val / 1000000).toFixed(axis.tickDecimals) + " MB"; |
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else if (val > 1000) |
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return (val / 1000).toFixed(axis.tickDecimals) + " kB"; |
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else |
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return val.toFixed(axis.tickDecimals) + " B"; |
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} |
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Time series data |
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================ |
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Time series are a bit more difficult than scalar data because |
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calendars don't follow a simple base 10 system. For many cases, Flot |
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abstracts most of this away, but it can still be a bit difficult to |
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get the data into Flot. So we'll first discuss the data format. |
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The time series support in Flot is based on Javascript timestamps, |
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i.e. everywhere a time value is expected or handed over, a Javascript |
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timestamp number is used. This is a number, not a Date object. A |
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Javascript timestamp is the number of milliseconds since January 1, |
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1970 00:00:00 UTC. This is almost the same as Unix timestamps, except it's |
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in milliseconds, so remember to multiply by 1000! |
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You can see a timestamp like this |
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alert((new Date()).getTime()) |
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Normally you want the timestamps to be displayed according to a |
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certain time zone, usually the time zone in which the data has been |
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produced. However, Flot always displays timestamps according to UTC. |
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It has to as the only alternative with core Javascript is to interpret |
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the timestamps according to the time zone that the visitor is in, |
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which means that the ticks will shift unpredictably with the time zone |
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and daylight savings of each visitor. |
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So given that there's no good support for custom time zones in |
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Javascript, you'll have to take care of this server-side. |
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The easiest way to think about it is to pretend that the data |
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production time zone is UTC, even if it isn't. So if you have a |
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datapoint at 2002-02-20 08:00, you can generate a timestamp for eight |
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o'clock UTC even if it really happened eight o'clock UTC+0200. |
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In PHP you can get an appropriate timestamp with |
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'strtotime("2002-02-20 UTC") * 1000', in Python with |
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'calendar.timegm(datetime_object.timetuple()) * 1000', in .NET with |
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something like: |
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public static int GetJavascriptTimestamp(System.DateTime input) |
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{ |
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System.TimeSpan span = new System.TimeSpan(System.DateTime.Parse("1/1/1970").Ticks); |
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System.DateTime time = input.Subtract(span); |
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return (long)(time.Ticks / 10000); |
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} |
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Javascript also has some support for parsing date strings, so it is |
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possible to generate the timestamps manually client-side. |
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If you've already got the real UTC timestamp, it's too late to use the |
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pretend trick described above. But you can fix up the timestamps by |
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adding the time zone offset, e.g. for UTC+0200 you would add 2 hours |
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to the UTC timestamp you got. Then it'll look right on the plot. Most |
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programming environments have some means of getting the timezone |
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offset for a specific date (note that you need to get the offset for |
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each individual timestamp to account for daylight savings). |
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Once you've gotten the timestamps into the data and specified "time" |
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as the axis mode, Flot will automatically generate relevant ticks and |
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format them. As always, you can tweak the ticks via the "ticks" option |
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- just remember that the values should be timestamps (numbers), not |
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Date objects. |
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|
376 |
Tick generation and formatting can also be controlled separately |
|
|
377 |
through the following axis options: |
|
|
378 |
|
|
|
379 |
minTickSize: array |
|
|
380 |
timeformat: null or format string |
|
|
381 |
monthNames: null or array of size 12 of strings |
|
|
382 |
twelveHourClock: boolean |
|
|
383 |
|
|
|
384 |
Here "timeformat" is a format string to use. You might use it like |
|
|
385 |
this: |
|
|
386 |
|
|
|
387 |
xaxis: { |
|
|
388 |
mode: "time" |
|
|
389 |
timeformat: "%y/%m/%d" |
|
|
390 |
} |
|
|
391 |
|
|
|
392 |
This will result in tick labels like "2000/12/24". The following |
|
|
393 |
specifiers are supported |
|
|
394 |
|
|
|
395 |
%h: hours |
|
|
396 |
%H: hours (left-padded with a zero) |
|
|
397 |
%M: minutes (left-padded with a zero) |
|
|
398 |
%S: seconds (left-padded with a zero) |
|
|
399 |
%d: day of month (1-31) |
|
|
400 |
%m: month (1-12) |
|
|
401 |
%y: year (four digits) |
|
|
402 |
%b: month name (customizable) |
|
|
403 |
%p: am/pm, additionally switches %h/%H to 12 hour instead of 24 |
|
|
404 |
%P: AM/PM (uppercase version of %p) |
|
|
405 |
|
|
|
406 |
You can customize the month names with the "monthNames" option. For |
|
|
407 |
instance, for Danish you might specify: |
|
|
408 |
|
|
|
409 |
monthNames: ["jan", "feb", "mar", "apr", "maj", "jun", "jul", "aug", "sep", "okt", "nov", "dec"] |
|
|
410 |
|
|
|
411 |
If you set "twelveHourClock" to true, the autogenerated timestamps |
|
|
412 |
will use 12 hour AM/PM timestamps instead of 24 hour. |
|
|
413 |
|
|
|
414 |
The format string and month names are used by a very simple built-in |
|
|
415 |
format function that takes a date object, a format string (and |
|
|
416 |
optionally an array of month names) and returns the formatted string. |
|
|
417 |
If needed, you can access it as $.plot.formatDate(date, formatstring, |
|
|
418 |
monthNames) or even replace it with another more advanced function |
|
|
419 |
from a date library if you're feeling adventurous. |
|
|
420 |
|
|
|
421 |
If everything else fails, you can control the formatting by specifying |
|
|
422 |
a custom tick formatter function as usual. Here's a simple example |
|
|
423 |
which will format December 24 as 24/12: |
|
|
424 |
|
|
|
425 |
tickFormatter: function (val, axis) { |
|
|
426 |
var d = new Date(val); |
|
|
427 |
return d.getUTCDate() + "/" + (d.getUTCMonth() + 1); |
|
|
428 |
} |
|
|
429 |
|
|
|
430 |
Note that for the time mode "tickSize" and "minTickSize" are a bit |
|
|
431 |
special in that they are arrays on the form "[value, unit]" where unit |
|
|
432 |
is one of "second", "minute", "hour", "day", "month" and "year". So |
|
|
433 |
you can specify |
|
|
434 |
|
|
|
435 |
minTickSize: [1, "month"] |
|
|
436 |
|
|
|
437 |
to get a tick interval size of at least 1 month and correspondingly, |
|
|
438 |
if axis.tickSize is [2, "day"] in the tick formatter, the ticks have |
|
|
439 |
been produced with two days in-between. |
|
|
440 |
|
|
|
441 |
|
|
|
442 |
|
|
|
443 |
Customizing the data series |
|
|
444 |
=========================== |
|
|
445 |
|
|
|
446 |
series: { |
|
|
447 |
lines, points, bars: { |
|
|
448 |
show: boolean |
|
|
449 |
lineWidth: number |
|
|
450 |
fill: boolean or number |
|
|
451 |
fillColor: null or color/gradient |
|
|
452 |
} |
|
|
453 |
|
|
|
454 |
points: { |
|
|
455 |
radius: number |
|
|
456 |
} |
|
|
457 |
|
|
|
458 |
bars: { |
|
|
459 |
barWidth: number |
|
|
460 |
align: "left" or "center" |
|
|
461 |
horizontal: boolean |
|
|
462 |
} |
|
|
463 |
|
|
|
464 |
lines: { |
|
|
465 |
steps: boolean |
|
|
466 |
} |
|
|
467 |
|
|
|
468 |
shadowSize: number |
|
|
469 |
} |
|
|
470 |
|
|
|
471 |
colors: [ color1, color2, ... ] |
|
|
472 |
|
|
|
473 |
The options inside "series: {}" are copied to each of the series. So |
|
|
474 |
you can specify that all series should have bars by putting it in the |
|
|
475 |
global options, or override it for individual series by specifying |
|
|
476 |
bars in a particular the series object in the array of data. |
|
|
477 |
|
|
|
478 |
The most important options are "lines", "points" and "bars" that |
|
|
479 |
specify whether and how lines, points and bars should be shown for |
|
|
480 |
each data series. In case you don't specify anything at all, Flot will |
|
|
481 |
default to showing lines (you can turn this off with |
|
|
482 |
lines: { show: false}). You can specify the various types |
|
|
483 |
independently of each other, and Flot will happily draw each of them |
|
|
484 |
in turn (this is probably only useful for lines and points), e.g. |
|
|
485 |
|
|
|
486 |
var options = { |
|
|
487 |
series: { |
|
|
488 |
lines: { show: true, fill: true, fillColor: "rgba(255, 255, 255, 0.8)" }, |
|
|
489 |
points: { show: true, fill: false } |
|
|
490 |
} |
|
|
491 |
}; |
|
|
492 |
|
|
|
493 |
"lineWidth" is the thickness of the line or outline in pixels. You can |
|
|
494 |
set it to 0 to prevent a line or outline from being drawn; this will |
|
|
495 |
also hide the shadow. |
|
|
496 |
|
|
|
497 |
"fill" is whether the shape should be filled. For lines, this produces |
|
|
498 |
area graphs. You can use "fillColor" to specify the color of the fill. |
|
|
499 |
If "fillColor" evaluates to false (default for everything except |
|
|
500 |
points which are filled with white), the fill color is auto-set to the |
|
|
501 |
color of the data series. You can adjust the opacity of the fill by |
|
|
502 |
setting fill to a number between 0 (fully transparent) and 1 (fully |
|
|
503 |
opaque). |
|
|
504 |
|
|
|
505 |
For bars, fillColor can be a gradient, see the gradient documentation |
|
|
506 |
below. "barWidth" is the width of the bars in units of the x axis (or |
|
|
507 |
the y axis if "horizontal" is true), contrary to most other measures |
|
|
508 |
that are specified in pixels. For instance, for time series the unit |
|
|
509 |
is milliseconds so 24 * 60 * 60 * 1000 produces bars with the width of |
|
|
510 |
a day. "align" specifies whether a bar should be left-aligned |
|
|
511 |
(default) or centered on top of the value it represents. When |
|
|
512 |
"horizontal" is on, the bars are drawn horizontally, i.e. from the y |
|
|
513 |
axis instead of the x axis; note that the bar end points are still |
|
|
514 |
defined in the same way so you'll probably want to swap the |
|
|
515 |
coordinates if you've been plotting vertical bars first. |
|
|
516 |
|
|
|
517 |
For lines, "steps" specifies whether two adjacent data points are |
|
|
518 |
connected with a straight (possibly diagonal) line or with first a |
|
|
519 |
horizontal and then a vertical line. Note that this transforms the |
|
|
520 |
data by adding extra points. |
|
|
521 |
|
|
|
522 |
"shadowSize" is the default size of shadows in pixels. Set it to 0 to |
|
|
523 |
remove shadows. |
|
|
524 |
|
|
|
525 |
The "colors" array specifies a default color theme to get colors for |
|
|
526 |
the data series from. You can specify as many colors as you like, like |
|
|
527 |
this: |
|
|
528 |
|
|
|
529 |
colors: ["#d18b2c", "#dba255", "#919733"] |
|
|
530 |
|
|
|
531 |
If there are more data series than colors, Flot will try to generate |
|
|
532 |
extra colors by lightening and darkening colors in the theme. |
|
|
533 |
|
|
|
534 |
|
|
|
535 |
Customizing the grid |
|
|
536 |
==================== |
|
|
537 |
|
|
|
538 |
grid: { |
|
|
539 |
show: boolean |
|
|
540 |
aboveData: boolean |
|
|
541 |
color: color |
|
|
542 |
backgroundColor: color/gradient or null |
|
|
543 |
tickColor: color |
|
|
544 |
labelMargin: number |
|
|
545 |
markings: array of markings or (fn: axes -> array of markings) |
|
|
546 |
borderWidth: number |
|
|
547 |
borderColor: color or null |
|
|
548 |
clickable: boolean |
|
|
549 |
hoverable: boolean |
|
|
550 |
autoHighlight: boolean |
|
|
551 |
mouseActiveRadius: number |
|
|
552 |
} |
|
|
553 |
|
|
|
554 |
The grid is the thing with the axes and a number of ticks. "color" is |
|
|
555 |
the color of the grid itself whereas "backgroundColor" specifies the |
|
|
556 |
background color inside the grid area. The default value of null means |
|
|
557 |
that the background is transparent. You can also set a gradient, see |
|
|
558 |
the gradient documentation below. |
|
|
559 |
|
|
|
560 |
You can turn off the whole grid including tick labels by setting |
|
|
561 |
"show" to false. "aboveData" determines whether the grid is drawn on |
|
|
562 |
above the data or below (below is default). |
|
|
563 |
|
|
|
564 |
"tickColor" is the color of the ticks and "labelMargin" is the spacing |
|
|
565 |
between tick labels and the grid. Note that you can style the tick |
|
|
566 |
labels with CSS, e.g. to change the color. They have class "tickLabel". |
|
|
567 |
"borderWidth" is the width of the border around the plot. Set it to 0 |
|
|
568 |
to disable the border. You can also set "borderColor" if you want the |
|
|
569 |
border to have a different color than the grid lines. |
|
|
570 |
|
|
|
571 |
"markings" is used to draw simple lines and rectangular areas in the |
|
|
572 |
background of the plot. You can either specify an array of ranges on |
|
|
573 |
the form { xaxis: { from, to }, yaxis: { from, to } } (secondary axis |
|
|
574 |
coordinates with x2axis/y2axis) or with a function that returns such |
|
|
575 |
an array given the axes for the plot in an object as the first |
|
|
576 |
parameter. |
|
|
577 |
|
|
|
578 |
You can set the color of markings by specifying "color" in the ranges |
|
|
579 |
object. Here's an example array: |
|
|
580 |
|
|
|
581 |
markings: [ { xaxis: { from: 0, to: 2 }, yaxis: { from: 10, to: 10 }, color: "#bb0000" }, ... ] |
|
|
582 |
|
|
|
583 |
If you leave out one of the values, that value is assumed to go to the |
|
|
584 |
border of the plot. So for example if you only specify { xaxis: { |
|
|
585 |
from: 0, to: 2 } } it means an area that extends from the top to the |
|
|
586 |
bottom of the plot in the x range 0-2. |
|
|
587 |
|
|
|
588 |
A line is drawn if from and to are the same, e.g. |
|
|
589 |
|
|
|
590 |
markings: [ { yaxis: { from: 1, to: 1 } }, ... ] |
|
|
591 |
|
|
|
592 |
would draw a line parallel to the x axis at y = 1. You can control the |
|
|
593 |
line width with "lineWidth" in the range object. |
|
|
594 |
|
|
|
595 |
An example function might look like this: |
|
|
596 |
|
|
|
597 |
markings: function (axes) { |
|
|
598 |
var markings = []; |
|
|
599 |
for (var x = Math.floor(axes.xaxis.min); x < axes.xaxis.max; x += 2) |
|
|
600 |
markings.push({ xaxis: { from: x, to: x + 1 } }); |
|
|
601 |
return markings; |
|
|
602 |
} |
|
|
603 |
|
|
|
604 |
|
|
|
605 |
If you set "clickable" to true, the plot will listen for click events |
|
|
606 |
on the plot area and fire a "plotclick" event on the placeholder with |
|
|
607 |
a position and a nearby data item object as parameters. The coordinates |
|
|
608 |
are available both in the unit of the axes (not in pixels) and in |
|
|
609 |
global screen coordinates. |
|
|
610 |
|
|
|
611 |
Likewise, if you set "hoverable" to true, the plot will listen for |
|
|
612 |
mouse move events on the plot area and fire a "plothover" event with |
|
|
613 |
the same parameters as the "plotclick" event. If "autoHighlight" is |
|
|
614 |
true (the default), nearby data items are highlighted automatically. |
|
|
615 |
If needed, you can disable highlighting and control it yourself with |
|
|
616 |
the highlight/unhighlight plot methods described elsewhere. |
|
|
617 |
|
|
|
618 |
You can use "plotclick" and "plothover" events like this: |
|
|
619 |
|
|
|
620 |
$.plot($("#placeholder"), [ d ], { grid: { clickable: true } }); |
|
|
621 |
|
|
|
622 |
$("#placeholder").bind("plotclick", function (event, pos, item) { |
|
|
623 |
alert("You clicked at " + pos.x + ", " + pos.y); |
|
|
624 |
// secondary axis coordinates if present are in pos.x2, pos.y2, |
|
|
625 |
// if you need global screen coordinates, they are pos.pageX, pos.pageY |
|
|
626 |
|
|
|
627 |
if (item) { |
|
|
628 |
highlight(item.series, item.datapoint); |
|
|
629 |
alert("You clicked a point!"); |
|
|
630 |
} |
|
|
631 |
}); |
|
|
632 |
|
|
|
633 |
The item object in this example is either null or a nearby object on the form: |
|
|
634 |
|
|
|
635 |
item: { |
|
|
636 |
datapoint: the point, e.g. [0, 2] |
|
|
637 |
dataIndex: the index of the point in the data array |
|
|
638 |
series: the series object |
|
|
639 |
seriesIndex: the index of the series |
|
|
640 |
pageX, pageY: the global screen coordinates of the point |
|
|
641 |
} |
|
|
642 |
|
|
|
643 |
For instance, if you have specified the data like this |
|
|
644 |
|
|
|
645 |
$.plot($("#placeholder"), [ { label: "Foo", data: [[0, 10], [7, 3]] } ], ...); |
|
|
646 |
|
|
|
647 |
and the mouse is near the point (7, 3), "datapoint" is [7, 3], |
|
|
648 |
"dataIndex" will be 1, "series" is a normalized series object with |
|
|
649 |
among other things the "Foo" label in series.label and the color in |
|
|
650 |
series.color, and "seriesIndex" is 0. Note that plugins and options |
|
|
651 |
that transform the data can shift the indexes from what you specified |
|
|
652 |
in the original data array. |
|
|
653 |
|
|
|
654 |
If you use the above events to update some other information and want |
|
|
655 |
to clear out that info in case the mouse goes away, you'll probably |
|
|
656 |
also need to listen to "mouseout" events on the placeholder div. |
|
|
657 |
|
|
|
658 |
"mouseActiveRadius" specifies how far the mouse can be from an item |
|
|
659 |
and still activate it. If there are two or more points within this |
|
|
660 |
radius, Flot chooses the closest item. For bars, the top-most bar |
|
|
661 |
(from the latest specified data series) is chosen. |
|
|
662 |
|
|
|
663 |
If you want to disable interactivity for a specific data series, you |
|
|
664 |
can set "hoverable" and "clickable" to false in the options for that |
|
|
665 |
series, like this { data: [...], label: "Foo", clickable: false }. |
|
|
666 |
|
|
|
667 |
|
|
|
668 |
Specifying gradients |
|
|
669 |
==================== |
|
|
670 |
|
|
|
671 |
A gradient is specified like this: |
|
|
672 |
|
|
|
673 |
{ colors: [ color1, color2, ... ] } |
|
|
674 |
|
|
|
675 |
For instance, you might specify a background on the grid going from |
|
|
676 |
black to gray like this: |
|
|
677 |
|
|
|
678 |
grid: { |
|
|
679 |
backgroundColor: { colors: ["#000", "#999"] } |
|
|
680 |
} |
|
|
681 |
|
|
|
682 |
For the series you can specify the gradient as an object that |
|
|
683 |
specifies the scaling of the brightness and the opacity of the series |
|
|
684 |
color, e.g. |
|
|
685 |
|
|
|
686 |
{ colors: [{ opacity: 0.8 }, { brightness: 0.6, opacity: 0.8 } ] } |
|
|
687 |
|
|
|
688 |
where the first color simply has its alpha scaled, whereas the second |
|
|
689 |
is also darkened. For instance, for bars the following makes the bars |
|
|
690 |
gradually disappear, without outline: |
|
|
691 |
|
|
|
692 |
bars: { |
|
|
693 |
show: true, |
|
|
694 |
lineWidth: 0, |
|
|
695 |
fill: true, |
|
|
696 |
fillColor: { colors: [ { opacity: 0.8 }, { opacity: 0.1 } ] } |
|
|
697 |
} |
|
|
698 |
|
|
|
699 |
Flot currently only supports vertical gradients drawn from top to |
|
|
700 |
bottom because that's what works with IE. |
|
|
701 |
|
|
|
702 |
|
|
|
703 |
Plot Methods |
|
|
704 |
------------ |
|
|
705 |
|
|
|
706 |
The Plot object returned from the plot function has some methods you |
|
|
707 |
can call: |
|
|
708 |
|
|
|
709 |
- highlight(series, datapoint) |
|
|
710 |
|
|
|
711 |
Highlight a specific datapoint in the data series. You can either |
|
|
712 |
specify the actual objects, e.g. if you got them from a |
|
|
713 |
"plotclick" event, or you can specify the indices, e.g. |
|
|
714 |
highlight(1, 3) to highlight the fourth point in the second series |
|
|
715 |
(remember, zero-based indexing). |
|
|
716 |
|
|
|
717 |
|
|
|
718 |
- unhighlight(series, datapoint) or unhighlight() |
|
|
719 |
|
|
|
720 |
Remove the highlighting of the point, same parameters as |
|
|
721 |
highlight. |
|
|
722 |
|
|
|
723 |
If you call unhighlight with no parameters, e.g. as |
|
|
724 |
plot.unhighlight(), all current highlights are removed. |
|
|
725 |
|
|
|
726 |
|
|
|
727 |
- setData(data) |
|
|
728 |
|
|
|
729 |
You can use this to reset the data used. Note that axis scaling, |
|
|
730 |
ticks, legend etc. will not be recomputed (use setupGrid() to do |
|
|
731 |
that). You'll probably want to call draw() afterwards. |
|
|
732 |
|
|
|
733 |
You can use this function to speed up redrawing a small plot if |
|
|
734 |
you know that the axes won't change. Put in the new data with |
|
|
735 |
setData(newdata), call draw(), and you're good to go. Note that |
|
|
736 |
for large datasets, almost all the time is consumed in draw() |
|
|
737 |
plotting the data so in this case don't bother. |
|
|
738 |
|
|
|
739 |
|
|
|
740 |
- setupGrid() |
|
|
741 |
|
|
|
742 |
Recalculate and set axis scaling, ticks, legend etc. |
|
|
743 |
|
|
|
744 |
Note that because of the drawing model of the canvas, this |
|
|
745 |
function will immediately redraw (actually reinsert in the DOM) |
|
|
746 |
the labels and the legend, but not the actual tick lines because |
|
|
747 |
they're drawn on the canvas. You need to call draw() to get the |
|
|
748 |
canvas redrawn. |
|
|
749 |
|
|
|
750 |
- draw() |
|
|
751 |
|
|
|
752 |
Redraws the plot canvas. |
|
|
753 |
|
|
|
754 |
- triggerRedrawOverlay() |
|
|
755 |
|
|
|
756 |
Schedules an update of an overlay canvas used for drawing |
|
|
757 |
interactive things like a selection and point highlights. This |
|
|
758 |
is mostly useful for writing plugins. The redraw doesn't happen |
|
|
759 |
immediately, instead a timer is set to catch multiple successive |
|
|
760 |
redraws (e.g. from a mousemove). |
|
|
761 |
|
|
|
762 |
- width()/height() |
|
|
763 |
|
|
|
764 |
Gets the width and height of the plotting area inside the grid. |
|
|
765 |
This is smaller than the canvas or placeholder dimensions as some |
|
|
766 |
extra space is needed (e.g. for labels). |
|
|
767 |
|
|
|
768 |
- offset() |
|
|
769 |
|
|
|
770 |
Returns the offset of the plotting area inside the grid relative |
|
|
771 |
to the document, useful for instance for calculating mouse |
|
|
772 |
positions (event.pageX/Y minus this offset is the pixel position |
|
|
773 |
inside the plot). |
|
|
774 |
|
|
|
775 |
- pointOffset({ x: xpos, y: ypos }) |
|
|
776 |
|
|
|
777 |
Returns the calculated offset of the data point at (x, y) in data |
|
|
778 |
space within the placeholder div. If you are working with dual axes, you |
|
|
779 |
can specify the x and y axis references, e.g. |
|
|
780 |
|
|
|
781 |
o = pointOffset({ x: xpos, y: ypos, xaxis: 2, yaxis: 2 }) |
|
|
782 |
// o.left and o.top now contains the offset within the div |
|
|
783 |
|
|
|
784 |
|
|
|
785 |
There are also some members that let you peek inside the internal |
|
|
786 |
workings of Flot which is useful in some cases. Note that if you change |
|
|
787 |
something in the objects returned, you're changing the objects used by |
|
|
788 |
Flot to keep track of its state, so be careful. |
|
|
789 |
|
|
|
790 |
- getData() |
|
|
791 |
|
|
|
792 |
Returns an array of the data series currently used in normalized |
|
|
793 |
form with missing settings filled in according to the global |
|
|
794 |
options. So for instance to find out what color Flot has assigned |
|
|
795 |
to the data series, you could do this: |
|
|
796 |
|
|
|
797 |
var series = plot.getData(); |
|
|
798 |
for (var i = 0; i < series.length; ++i) |
|
|
799 |
alert(series[i].color); |
|
|
800 |
|
|
|
801 |
A notable other interesting field besides color is datapoints |
|
|
802 |
which has a field "points" with the normalized data points in a |
|
|
803 |
flat array (the field "pointsize" is the increment in the flat |
|
|
804 |
array to get to the next point so for a dataset consisting only of |
|
|
805 |
(x,y) pairs it would be 2). |
|
|
806 |
|
|
|
807 |
- getAxes() |
|
|
808 |
|
|
|
809 |
Gets an object with the axes settings as { xaxis, yaxis, x2axis, |
|
|
810 |
y2axis }. |
|
|
811 |
|
|
|
812 |
Various things are stuffed inside an axis object, e.g. you could |
|
|
813 |
use getAxes().xaxis.ticks to find out what the ticks are for the |
|
|
814 |
xaxis. Two other useful attributes are p2c and c2p, functions for |
|
|
815 |
transforming from data point space to the canvas plot space and |
|
|
816 |
back. Both returns values that are offset with the plot offset. |
|
|
817 |
|
|
|
818 |
- getPlaceholder() |
|
|
819 |
|
|
|
820 |
Returns placeholder that the plot was put into. This can be useful |
|
|
821 |
for plugins for adding DOM elements or firing events. |
|
|
822 |
|
|
|
823 |
- getCanvas() |
|
|
824 |
|
|
|
825 |
Returns the canvas used for drawing in case you need to hack on it |
|
|
826 |
yourself. You'll probably need to get the plot offset too. |
|
|
827 |
|
|
|
828 |
- getPlotOffset() |
|
|
829 |
|
|
|
830 |
Gets the offset that the grid has within the canvas as an object |
|
|
831 |
with distances from the canvas edges as "left", "right", "top", |
|
|
832 |
"bottom". I.e., if you draw a circle on the canvas with the center |
|
|
833 |
placed at (left, top), its center will be at the top-most, left |
|
|
834 |
corner of the grid. |
|
|
835 |
|
|
|
836 |
- getOptions() |
|
|
837 |
|
|
|
838 |
Gets the options for the plot, in a normalized format with default |
|
|
839 |
values filled in. |
|
|
840 |
|
|
|
841 |
|
|
|
842 |
Hooks |
|
|
843 |
===== |
|
|
844 |
|
|
|
845 |
In addition to the public methods, the Plot object also has some hooks |
|
|
846 |
that can be used to modify the plotting process. You can install a |
|
|
847 |
callback function at various points in the process, the function then |
|
|
848 |
gets access to the internal data structures in Flot. |
|
|
849 |
|
|
|
850 |
Here's an overview of the phases Flot goes through: |
|
|
851 |
|
|
|
852 |
1. Plugin initialization, parsing options |
|
|
853 |
|
|
|
854 |
2. Constructing the canvases used for drawing |
|
|
855 |
|
|
|
856 |
3. Set data: parsing data specification, calculating colors, |
|
|
857 |
copying raw data points into internal format, |
|
|
858 |
normalizing them, finding max/min for axis auto-scaling |
|
|
859 |
|
|
|
860 |
4. Grid setup: calculating axis spacing, ticks, inserting tick |
|
|
861 |
labels, the legend |
|
|
862 |
|
|
|
863 |
5. Draw: drawing the grid, drawing each of the series in turn |
|
|
864 |
|
|
|
865 |
6. Setting up event handling for interactive features |
|
|
866 |
|
|
|
867 |
7. Responding to events, if any |
|
|
868 |
|
|
|
869 |
Each hook is simply a function which is put in the appropriate array. |
|
|
870 |
You can add them through the "hooks" option, and they are also available |
|
|
871 |
after the plot is constructed as the "hooks" attribute on the returned |
|
|
872 |
plot object, e.g. |
|
|
873 |
|
|
|
874 |
// define a simple draw hook |
|
|
875 |
function hellohook(plot, canvascontext) { alert("hello!"); }; |
|
|
876 |
|
|
|
877 |
// pass it in, in an array since we might want to specify several |
|
|
878 |
var plot = $.plot(placeholder, data, { hooks: { draw: [hellohook] } }); |
|
|
879 |
|
|
|
880 |
// we can now find it again in plot.hooks.draw[0] unless a plugin |
|
|
881 |
// has added other hooks |
|
|
882 |
|
|
|
883 |
The available hooks are described below. All hook callbacks get the |
|
|
884 |
plot object as first parameter. You can find some examples of defined |
|
|
885 |
hooks in the plugins bundled with Flot. |
|
|
886 |
|
|
|
887 |
- processOptions [phase 1] |
|
|
888 |
|
|
|
889 |
function(plot, options) |
|
|
890 |
|
|
|
891 |
Called after Flot has parsed and merged options. Useful in the |
|
|
892 |
instance where customizations beyond simple merging of default |
|
|
893 |
values is needed. A plugin might use it to detect that it has been |
|
|
894 |
enabled and then turn on or off other options. |
|
|
895 |
|
|
|
896 |
|
|
|
897 |
- processRawData [phase 3] |
|
|
898 |
|
|
|
899 |
function(plot, series, data, datapoints) |
|
|
900 |
|
|
|
901 |
Called before Flot copies and normalizes the raw data for the given |
|
|
902 |
series. If the function fills in datapoints.points with normalized |
|
|
903 |
points and sets datapoints.pointsize to the size of the points, |
|
|
904 |
Flot will skip the copying/normalization step for this series. |
|
|
905 |
|
|
|
906 |
In any case, you might be interested in setting datapoints.format, |
|
|
907 |
an array of objects for specifying how a point is normalized and |
|
|
908 |
how it interferes with axis scaling. |
|
|
909 |
|
|
|
910 |
The default format array for points is something along the lines of: |
|
|
911 |
|
|
|
912 |
[ |
|
|
913 |
{ x: true, number: true, required: true }, |
|
|
914 |
{ y: true, number: true, required: true } |
|
|
915 |
] |
|
|
916 |
|
|
|
917 |
The first object means that for the first coordinate it should be |
|
|
918 |
taken into account when scaling the x axis, that it must be a |
|
|
919 |
number, and that it is required - so if it is null or cannot be |
|
|
920 |
converted to a number, the whole point will be zeroed out with |
|
|
921 |
nulls. Beyond these you can also specify "defaultValue", a value to |
|
|
922 |
use if the coordinate is null. This is for instance handy for bars |
|
|
923 |
where one can omit the third coordinate (the bottom of the bar) |
|
|
924 |
which then defaults to 0. |
|
|
925 |
|
|
|
926 |
|
|
|
927 |
- processDatapoints [phase 3] |
|
|
928 |
|
|
|
929 |
function(plot, series, datapoints) |
|
|
930 |
|
|
|
931 |
Called after normalization of the given series but before finding |
|
|
932 |
min/max of the data points. This hook is useful for implementing data |
|
|
933 |
transformations. "datapoints" contains the normalized data points in |
|
|
934 |
a flat array as datapoints.points with the size of a single point |
|
|
935 |
given in datapoints.pointsize. Here's a simple transform that |
|
|
936 |
multiplies all y coordinates by 2: |
|
|
937 |
|
|
|
938 |
function multiply(plot, series, datapoints) { |
|
|
939 |
var points = datapoints.points, ps = datapoints.pointsize; |
|
|
940 |
for (var i = 0; i < points.length; i += ps) |
|
|
941 |
points[i + 1] *= 2; |
|
|
942 |
} |
|
|
943 |
|
|
|
944 |
Note that you must leave datapoints in a good condition as Flot |
|
|
945 |
doesn't check it or do any normalization on it afterwards. |
|
|
946 |
|
|
|
947 |
|
|
|
948 |
- draw [phase 5] |
|
|
949 |
|
|
|
950 |
function(plot, canvascontext) |
|
|
951 |
|
|
|
952 |
Hook for drawing on the canvas. Called after the grid is drawn |
|
|
953 |
(unless it's disabled) and the series have been plotted (in case |
|
|
954 |
any points, lines or bars have been turned on). For examples of how |
|
|
955 |
to draw things, look at the source code. |
|
|
956 |
|
|
|
957 |
|
|
|
958 |
- bindEvents [phase 6] |
|
|
959 |
|
|
|
960 |
function(plot, eventHolder) |
|
|
961 |
|
|
|
962 |
Called after Flot has setup its event handlers. Should set any |
|
|
963 |
necessary event handlers on eventHolder, a jQuery object with the |
|
|
964 |
canvas, e.g. |
|
|
965 |
|
|
|
966 |
function (plot, eventHolder) { |
|
|
967 |
eventHolder.mousedown(function (e) { |
|
|
968 |
alert("You pressed the mouse at " + e.pageX + " " + e.pageY); |
|
|
969 |
}); |
|
|
970 |
} |
|
|
971 |
|
|
|
972 |
Interesting events include click, mousemove, mouseup/down. You can |
|
|
973 |
use all jQuery events. Usually, the event handlers will update the |
|
|
974 |
state by drawing something (add a drawOverlay hook and call |
|
|
975 |
triggerRedrawOverlay) or firing an externally visible event for |
|
|
976 |
user code. See the crosshair plugin for an example. |
|
|
977 |
|
|
|
978 |
Currently, eventHolder actually contains both the static canvas |
|
|
979 |
used for the plot itself and the overlay canvas used for |
|
|
980 |
interactive features because some versions of IE get the stacking |
|
|
981 |
order wrong. The hook only gets one event, though (either for the |
|
|
982 |
overlay or for the static canvas). |
|
|
983 |
|
|
|
984 |
|
|
|
985 |
- drawOverlay [phase 7] |
|
|
986 |
|
|
|
987 |
function (plot, canvascontext) |
|
|
988 |
|
|
|
989 |
The drawOverlay hook is used for interactive things that need a |
|
|
990 |
canvas to draw on. The model currently used by Flot works the way |
|
|
991 |
that an extra overlay canvas is positioned on top of the static |
|
|
992 |
canvas. This overlay is cleared and then completely redrawn |
|
|
993 |
whenever something interesting happens. This hook is called when |
|
|
994 |
the overlay canvas is to be redrawn. |
|
|
995 |
|
|
|
996 |
"canvascontext" is the 2D context of the overlay canvas. You can |
|
|
997 |
use this to draw things. You'll most likely need some of the |
|
|
998 |
metrics computed by Flot, e.g. plot.width()/plot.height(). See the |
|
|
999 |
crosshair plugin for an example. |
|
|
1000 |
|
|
|
1001 |
|
|
|
1002 |
|
|
|
1003 |
Plugins |
|
|
1004 |
------- |
|
|
1005 |
|
|
|
1006 |
Plugins extend the functionality of Flot. To use a plugin, simply |
|
|
1007 |
include its Javascript file after Flot in the HTML page. |
|
|
1008 |
|
|
|
1009 |
If you're worried about download size/latency, you can concatenate all |
|
|
1010 |
the plugins you use, and Flot itself for that matter, into one big file |
|
|
1011 |
(make sure you get the order right), then optionally run it through a |
|
|
1012 |
Javascript minifier such as YUI Compressor. |
|
|
1013 |
|
|
|
1014 |
Here's a brief explanation of how the plugin plumbings work: |
|
|
1015 |
|
|
|
1016 |
Each plugin registers itself in the global array $.plot.plugins. When |
|
|
1017 |
you make a new plot object with $.plot, Flot goes through this array |
|
|
1018 |
calling the "init" function of each plugin and merging default options |
|
|
1019 |
from its "option" attribute. The init function gets a reference to the |
|
|
1020 |
plot object created and uses this to register hooks and add new public |
|
|
1021 |
methods if needed. |
|
|
1022 |
|
|
|
1023 |
See the PLUGINS.txt file for details on how to write a plugin. As the |
|
|
1024 |
above description hints, it's actually pretty easy. |
|
|
1025 |
|