diff options
Diffstat (limited to 'ebus/webapp/static/lib/flot-0.7/API.txt')
| -rw-r--r-- | ebus/webapp/static/lib/flot-0.7/API.txt | 1201 |
1 files changed, 0 insertions, 1201 deletions
diff --git a/ebus/webapp/static/lib/flot-0.7/API.txt b/ebus/webapp/static/lib/flot-0.7/API.txt deleted file mode 100644 index 8a8dbc2..0000000 --- a/ebus/webapp/static/lib/flot-0.7/API.txt +++ /dev/null @@ -1,1201 +0,0 @@ -Flot Reference --------------- - -Consider a call to the plot function: - - var plot = $.plot(placeholder, data, options) - -The placeholder is a jQuery object or DOM element or jQuery expression -that the plot will be put into. This placeholder needs to have its -width and height set as explained in the README (go read that now if -you haven't, it's short). The plot will modify some properties of the -placeholder so it's recommended you simply pass in a div that you -don't use for anything else. Make sure you check any fancy styling -you apply to the div, e.g. background images have been reported to be a -problem on IE 7. - -The format of the data is documented below, as is the available -options. The plot object returned from the call has some methods you -can call. These are documented separately below. - -Note that in general Flot gives no guarantees if you change any of the -objects you pass in to the plot function or get out of it since -they're not necessarily deep-copied. - - -Data Format ------------ - -The data is an array of data series: - - [ series1, series2, ... ] - -A series can either be raw data or an object with properties. The raw -data format is an array of points: - - [ [x1, y1], [x2, y2], ... ] - -E.g. - - [ [1, 3], [2, 14.01], [3.5, 3.14] ] - -Note that to simplify the internal logic in Flot both the x and y -values must be numbers (even if specifying time series, see below for -how to do this). This is a common problem because you might retrieve -data from the database and serialize them directly to JSON without -noticing the wrong type. If you're getting mysterious errors, double -check that you're inputting numbers and not strings. - -If a null is specified as a point or if one of the coordinates is null -or couldn't be converted to a number, the point is ignored when -drawing. As a special case, a null value for lines is interpreted as a -line segment end, i.e. the points before and after the null value are -not connected. - -Lines and points take two coordinates. For filled lines and bars, you -can specify a third coordinate which is the bottom of the filled -area/bar (defaults to 0). - -The format of a single series object is as follows: - - { - color: color or number - data: rawdata - label: string - lines: specific lines options - bars: specific bars options - points: specific points options - xaxis: number - yaxis: number - clickable: boolean - hoverable: boolean - shadowSize: number - } - -You don't have to specify any of them except the data, the rest are -options that will get default values. Typically you'd only specify -label and data, like this: - - { - label: "y = 3", - data: [[0, 3], [10, 3]] - } - -The label is used for the legend, if you don't specify one, the series -will not show up in the legend. - -If you don't specify color, the series will get a color from the -auto-generated colors. The color is either a CSS color specification -(like "rgb(255, 100, 123)") or an integer that specifies which of -auto-generated colors to select, e.g. 0 will get color no. 0, etc. - -The latter is mostly useful if you let the user add and remove series, -in which case you can hard-code the color index to prevent the colors -from jumping around between the series. - -The "xaxis" and "yaxis" options specify which axis to use. The axes -are numbered from 1 (default), so { yaxis: 2} means that the series -should be plotted against the second y axis. - -"clickable" and "hoverable" can be set to false to disable -interactivity for specific series if interactivity is turned on in -the plot, see below. - -The rest of the options are all documented below as they are the same -as the default options passed in via the options parameter in the plot -commmand. When you specify them for a specific data series, they will -override the default options for the plot for that data series. - -Here's a complete example of a simple data specification: - - [ { label: "Foo", data: [ [10, 1], [17, -14], [30, 5] ] }, - { label: "Bar", data: [ [11, 13], [19, 11], [30, -7] ] } ] - - -Plot Options ------------- - -All options are completely optional. They are documented individually -below, to change them you just specify them in an object, e.g. - - var options = { - series: { - lines: { show: true }, - points: { show: true } - } - }; - - $.plot(placeholder, data, options); - - -Customizing the legend -====================== - - legend: { - show: boolean - labelFormatter: null or (fn: string, series object -> string) - labelBoxBorderColor: color - noColumns: number - position: "ne" or "nw" or "se" or "sw" - margin: number of pixels or [x margin, y margin] - backgroundColor: null or color - backgroundOpacity: number between 0 and 1 - container: null or jQuery object/DOM element/jQuery expression - } - -The legend is generated as a table with the data series labels and -small label boxes with the color of the series. If you want to format -the labels in some way, e.g. make them to links, you can pass in a -function for "labelFormatter". Here's an example that makes them -clickable: - - labelFormatter: function(label, series) { - // series is the series object for the label - return '<a href="#' + label + '">' + label + '</a>'; - } - -"noColumns" is the number of columns to divide the legend table into. -"position" specifies the overall placement of the legend within the -plot (top-right, top-left, etc.) and margin the distance to the plot -edge (this can be either a number or an array of two numbers like [x, -y]). "backgroundColor" and "backgroundOpacity" specifies the -background. The default is a partly transparent auto-detected -background. - -If you want the legend to appear somewhere else in the DOM, you can -specify "container" as a jQuery object/expression to put the legend -table into. The "position" and "margin" etc. options will then be -ignored. Note that Flot will overwrite the contents of the container. - - -Customizing the axes -==================== - - xaxis, yaxis: { - show: null or true/false - position: "bottom" or "top" or "left" or "right" - mode: null or "time" - - color: null or color spec - tickColor: null or color spec - - min: null or number - max: null or number - autoscaleMargin: null or number - - transform: null or fn: number -> number - inverseTransform: null or fn: number -> number - - ticks: null or number or ticks array or (fn: range -> ticks array) - tickSize: number or array - minTickSize: number or array - tickFormatter: (fn: number, object -> string) or string - tickDecimals: null or number - - labelWidth: null or number - labelHeight: null or number - reserveSpace: null or true - - tickLength: null or number - - alignTicksWithAxis: null or number - } - -All axes have the same kind of options. The following describes how to -configure one axis, see below for what to do if you've got more than -one x axis or y axis. - -If you don't set the "show" option (i.e. it is null), visibility is -auto-detected, i.e. the axis will show up if there's data associated -with it. You can override this by setting the "show" option to true or -false. - -The "position" option specifies where the axis is placed, bottom or -top for x axes, left or right for y axes. The "mode" option determines -how the data is interpreted, the default of null means as decimal -numbers. Use "time" for time series data, see the time series data -section. - -The "color" option determines the color of the labels and ticks for -the axis (default is the grid color). For more fine-grained control -you can also set the color of the ticks separately with "tickColor" -(otherwise it's autogenerated as the base color with some -transparency). - -The options "min"/"max" are the precise minimum/maximum value on the -scale. If you don't specify either of them, a value will automatically -be chosen based on the minimum/maximum data values. Note that Flot -always examines all the data values you feed to it, even if a -restriction on another axis may make some of them invisible (this -makes interactive use more stable). - -The "autoscaleMargin" is a bit esoteric: it's the fraction of margin -that the scaling algorithm will add to avoid that the outermost points -ends up on the grid border. Note that this margin is only applied when -a min or max value is not explicitly set. If a margin is specified, -the plot will furthermore extend the axis end-point to the nearest -whole tick. The default value is "null" for the x axes and 0.02 for y -axes which seems appropriate for most cases. - -"transform" and "inverseTransform" are callbacks you can put in to -change the way the data is drawn. You can design a function to -compress or expand certain parts of the axis non-linearly, e.g. -suppress weekends or compress far away points with a logarithm or some -other means. When Flot draws the plot, each value is first put through -the transform function. Here's an example, the x axis can be turned -into a natural logarithm axis with the following code: - - xaxis: { - transform: function (v) { return Math.log(v); }, - inverseTransform: function (v) { return Math.exp(v); } - } - -Similarly, for reversing the y axis so the values appear in inverse -order: - - yaxis: { - transform: function (v) { return -v; }, - inverseTransform: function (v) { return -v; } - } - -Note that for finding extrema, Flot assumes that the transform -function does not reorder values (it should be monotone). - -The inverseTransform is simply the inverse of the transform function -(so v == inverseTransform(transform(v)) for all relevant v). It is -required for converting from canvas coordinates to data coordinates, -e.g. for a mouse interaction where a certain pixel is clicked. If you -don't use any interactive features of Flot, you may not need it. - - -The rest of the options deal with the ticks. - -If you don't specify any ticks, a tick generator algorithm will make -some for you. The algorithm has two passes. It first estimates how -many ticks would be reasonable and uses this number to compute a nice -round tick interval size. Then it generates the ticks. - -You can specify how many ticks the algorithm aims for by setting -"ticks" to a number. The algorithm always tries to generate reasonably -round tick values so even if you ask for three ticks, you might get -five if that fits better with the rounding. If you don't want any -ticks at all, set "ticks" to 0 or an empty array. - -Another option is to skip the rounding part and directly set the tick -interval size with "tickSize". If you set it to 2, you'll get ticks at -2, 4, 6, etc. Alternatively, you can specify that you just don't want -ticks at a size less than a specific tick size with "minTickSize". -Note that for time series, the format is an array like [2, "month"], -see the next section. - -If you want to completely override the tick algorithm, you can specify -an array for "ticks", either like this: - - ticks: [0, 1.2, 2.4] - -Or like this where the labels are also customized: - - ticks: [[0, "zero"], [1.2, "one mark"], [2.4, "two marks"]] - -You can mix the two if you like. - -For extra flexibility you can specify a function as the "ticks" -parameter. The function will be called with an object with the axis -min and max and should return a ticks array. Here's a simplistic tick -generator that spits out intervals of pi, suitable for use on the x -axis for trigonometric functions: - - function piTickGenerator(axis) { - var res = [], i = Math.floor(axis.min / Math.PI); - do { - var v = i * Math.PI; - res.push([v, i + "\u03c0"]); - ++i; - } while (v < axis.max); - - return res; - } - -You can control how the ticks look like with "tickDecimals", the -number of decimals to display (default is auto-detected). - -Alternatively, for ultimate control over how ticks are formatted you can -provide a function to "tickFormatter". The function is passed two -parameters, the tick value and an axis object with information, and -should return a string. The default formatter looks like this: - - function formatter(val, axis) { - return val.toFixed(axis.tickDecimals); - } - -The axis object has "min" and "max" with the range of the axis, -"tickDecimals" with the number of decimals to round the value to and -"tickSize" with the size of the interval between ticks as calculated -by the automatic axis scaling algorithm (or specified by you). Here's -an example of a custom formatter: - - function suffixFormatter(val, axis) { - if (val > 1000000) - return (val / 1000000).toFixed(axis.tickDecimals) + " MB"; - else if (val > 1000) - return (val / 1000).toFixed(axis.tickDecimals) + " kB"; - else - return val.toFixed(axis.tickDecimals) + " B"; - } - -"labelWidth" and "labelHeight" specifies a fixed size of the tick -labels in pixels. They're useful in case you need to align several -plots. "reserveSpace" means that even if an axis isn't shown, Flot -should reserve space for it - it is useful in combination with -labelWidth and labelHeight for aligning multi-axis charts. - -"tickLength" is the length of the tick lines in pixels. By default, the -innermost axes will have ticks that extend all across the plot, while -any extra axes use small ticks. A value of null means use the default, -while a number means small ticks of that length - set it to 0 to hide -the lines completely. - -If you set "alignTicksWithAxis" to the number of another axis, e.g. -alignTicksWithAxis: 1, Flot will ensure that the autogenerated ticks -of this axis are aligned with the ticks of the other axis. This may -improve the looks, e.g. if you have one y axis to the left and one to -the right, because the grid lines will then match the ticks in both -ends. The trade-off is that the forced ticks won't necessarily be at -natural places. - - -Multiple axes -============= - -If you need more than one x axis or y axis, you need to specify for -each data series which axis they are to use, as described under the -format of the data series, e.g. { data: [...], yaxis: 2 } specifies -that a series should be plotted against the second y axis. - -To actually configure that axis, you can't use the xaxis/yaxis options -directly - instead there are two arrays in the options: - - xaxes: [] - yaxes: [] - -Here's an example of configuring a single x axis and two y axes (we -can leave options of the first y axis empty as the defaults are fine): - - { - xaxes: [ { position: "top" } ], - yaxes: [ { }, { position: "right", min: 20 } ] - } - -The arrays get their default values from the xaxis/yaxis settings, so -say you want to have all y axes start at zero, you can simply specify -yaxis: { min: 0 } instead of adding a min parameter to all the axes. - -Generally, the various interfaces in Flot dealing with data points -either accept an xaxis/yaxis parameter to specify which axis number to -use (starting from 1), or lets you specify the coordinate directly as -x2/x3/... or x2axis/x3axis/... instead of "x" or "xaxis". - - -Time series data -================ - -Time series are a bit more difficult than scalar data because -calendars don't follow a simple base 10 system. For many cases, Flot -abstracts most of this away, but it can still be a bit difficult to -get the data into Flot. So we'll first discuss the data format. - -The time series support in Flot is based on Javascript timestamps, -i.e. everywhere a time value is expected or handed over, a Javascript -timestamp number is used. This is a number, not a Date object. A -Javascript timestamp is the number of milliseconds since January 1, -1970 00:00:00 UTC. This is almost the same as Unix timestamps, except it's -in milliseconds, so remember to multiply by 1000! - -You can see a timestamp like this - - alert((new Date()).getTime()) - -Normally you want the timestamps to be displayed according to a -certain time zone, usually the time zone in which the data has been -produced. However, Flot always displays timestamps according to UTC. -It has to as the only alternative with core Javascript is to interpret -the timestamps according to the time zone that the visitor is in, -which means that the ticks will shift unpredictably with the time zone -and daylight savings of each visitor. - -So given that there's no good support for custom time zones in -Javascript, you'll have to take care of this server-side. - -The easiest way to think about it is to pretend that the data -production time zone is UTC, even if it isn't. So if you have a -datapoint at 2002-02-20 08:00, you can generate a timestamp for eight -o'clock UTC even if it really happened eight o'clock UTC+0200. - -In PHP you can get an appropriate timestamp with -'strtotime("2002-02-20 UTC") * 1000', in Python with -'calendar.timegm(datetime_object.timetuple()) * 1000', in .NET with -something like: - - public static int GetJavascriptTimestamp(System.DateTime input) - { - System.TimeSpan span = new System.TimeSpan(System.DateTime.Parse("1/1/1970").Ticks); - System.DateTime time = input.Subtract(span); - return (long)(time.Ticks / 10000); - } - -Javascript also has some support for parsing date strings, so it is -possible to generate the timestamps manually client-side. - -If you've already got the real UTC timestamp, it's too late to use the -pretend trick described above. But you can fix up the timestamps by -adding the time zone offset, e.g. for UTC+0200 you would add 2 hours -to the UTC timestamp you got. Then it'll look right on the plot. Most -programming environments have some means of getting the timezone -offset for a specific date (note that you need to get the offset for -each individual timestamp to account for daylight savings). - -Once you've gotten the timestamps into the data and specified "time" -as the axis mode, Flot will automatically generate relevant ticks and -format them. As always, you can tweak the ticks via the "ticks" option -- just remember that the values should be timestamps (numbers), not -Date objects. - -Tick generation and formatting can also be controlled separately -through the following axis options: - - minTickSize: array - timeformat: null or format string - monthNames: null or array of size 12 of strings - twelveHourClock: boolean - -Here "timeformat" is a format string to use. You might use it like -this: - - xaxis: { - mode: "time" - timeformat: "%y/%m/%d" - } - -This will result in tick labels like "2000/12/24". The following -specifiers are supported - - %h: hours - %H: hours (left-padded with a zero) - %M: minutes (left-padded with a zero) - %S: seconds (left-padded with a zero) - %d: day of month (1-31), use %0d for zero-padding - %m: month (1-12), use %0m for zero-padding - %y: year (four digits) - %b: month name (customizable) - %p: am/pm, additionally switches %h/%H to 12 hour instead of 24 - %P: AM/PM (uppercase version of %p) - -Inserting a zero like %0m or %0d means that the specifier will be -left-padded with a zero if it's only single-digit. So %y-%0m-%0d -results in unambigious ISO timestamps like 2007-05-10 (for May 10th). - -You can customize the month names with the "monthNames" option. For -instance, for Danish you might specify: - - monthNames: ["jan", "feb", "mar", "apr", "maj", "jun", "jul", "aug", "sep", "okt", "nov", "dec"] - -If you set "twelveHourClock" to true, the autogenerated timestamps -will use 12 hour AM/PM timestamps instead of 24 hour. - -The format string and month names are used by a very simple built-in -format function that takes a date object, a format string (and -optionally an array of month names) and returns the formatted string. -If needed, you can access it as $.plot.formatDate(date, formatstring, -monthNames) or even replace it with another more advanced function -from a date library if you're feeling adventurous. - -If everything else fails, you can control the formatting by specifying -a custom tick formatter function as usual. Here's a simple example -which will format December 24 as 24/12: - - tickFormatter: function (val, axis) { - var d = new Date(val); - return d.getUTCDate() + "/" + (d.getUTCMonth() + 1); - } - -Note that for the time mode "tickSize" and "minTickSize" are a bit -special in that they are arrays on the form "[value, unit]" where unit -is one of "second", "minute", "hour", "day", "month" and "year". So -you can specify - - minTickSize: [1, "month"] - -to get a tick interval size of at least 1 month and correspondingly, -if axis.tickSize is [2, "day"] in the tick formatter, the ticks have -been produced with two days in-between. - - - -Customizing the data series -=========================== - - series: { - lines, points, bars: { - show: boolean - lineWidth: number - fill: boolean or number - fillColor: null or color/gradient - } - - points: { - radius: number - symbol: "circle" or function - } - - bars: { - barWidth: number - align: "left" or "center" - horizontal: boolean - } - - lines: { - steps: boolean - } - - shadowSize: number - } - - colors: [ color1, color2, ... ] - -The options inside "series: {}" are copied to each of the series. So -you can specify that all series should have bars by putting it in the -global options, or override it for individual series by specifying -bars in a particular the series object in the array of data. - -The most important options are "lines", "points" and "bars" that -specify whether and how lines, points and bars should be shown for -each data series. In case you don't specify anything at all, Flot will -default to showing lines (you can turn this off with -lines: { show: false }). You can specify the various types -independently of each other, and Flot will happily draw each of them -in turn (this is probably only useful for lines and points), e.g. - - var options = { - series: { - lines: { show: true, fill: true, fillColor: "rgba(255, 255, 255, 0.8)" }, - points: { show: true, fill: false } - } - }; - -"lineWidth" is the thickness of the line or outline in pixels. You can -set it to 0 to prevent a line or outline from being drawn; this will -also hide the shadow. - -"fill" is whether the shape should be filled. For lines, this produces -area graphs. You can use "fillColor" to specify the color of the fill. -If "fillColor" evaluates to false (default for everything except -points which are filled with white), the fill color is auto-set to the -color of the data series. You can adjust the opacity of the fill by -setting fill to a number between 0 (fully transparent) and 1 (fully -opaque). - -For bars, fillColor can be a gradient, see the gradient documentation -below. "barWidth" is the width of the bars in units of the x axis (or -the y axis if "horizontal" is true), contrary to most other measures -that are specified in pixels. For instance, for time series the unit -is milliseconds so 24 * 60 * 60 * 1000 produces bars with the width of -a day. "align" specifies whether a bar should be left-aligned -(default) or centered on top of the value it represents. When -"horizontal" is on, the bars are drawn horizontally, i.e. from the y -axis instead of the x axis; note that the bar end points are still -defined in the same way so you'll probably want to swap the -coordinates if you've been plotting vertical bars first. - -For lines, "steps" specifies whether two adjacent data points are -connected with a straight (possibly diagonal) line or with first a -horizontal and then a vertical line. Note that this transforms the -data by adding extra points. - -For points, you can specify the radius and the symbol. The only -built-in symbol type is circles, for other types you can use a plugin -or define them yourself by specifying a callback: - - function cross(ctx, x, y, radius, shadow) { - var size = radius * Math.sqrt(Math.PI) / 2; - ctx.moveTo(x - size, y - size); - ctx.lineTo(x + size, y + size); - ctx.moveTo(x - size, y + size); - ctx.lineTo(x + size, y - size); - } - -The parameters are the drawing context, x and y coordinates of the -center of the point, a radius which corresponds to what the circle -would have used and whether the call is to draw a shadow (due to -limited canvas support, shadows are currently faked through extra -draws). It's good practice to ensure that the area covered by the -symbol is the same as for the circle with the given radius, this -ensures that all symbols have approximately the same visual weight. - -"shadowSize" is the default size of shadows in pixels. Set it to 0 to -remove shadows. - -The "colors" array specifies a default color theme to get colors for -the data series from. You can specify as many colors as you like, like -this: - - colors: ["#d18b2c", "#dba255", "#919733"] - -If there are more data series than colors, Flot will try to generate -extra colors by lightening and darkening colors in the theme. - - -Customizing the grid -==================== - - grid: { - show: boolean - aboveData: boolean - color: color - backgroundColor: color/gradient or null - labelMargin: number - axisMargin: number - markings: array of markings or (fn: axes -> array of markings) - borderWidth: number - borderColor: color or null - minBorderMargin: number or null - clickable: boolean - hoverable: boolean - autoHighlight: boolean - mouseActiveRadius: number - } - -The grid is the thing with the axes and a number of ticks. Many of the -things in the grid are configured under the individual axes, but not -all. "color" is the color of the grid itself whereas "backgroundColor" -specifies the background color inside the grid area, here null means -that the background is transparent. You can also set a gradient, see -the gradient documentation below. - -You can turn off the whole grid including tick labels by setting -"show" to false. "aboveData" determines whether the grid is drawn -above the data or below (below is default). - -"labelMargin" is the space in pixels between tick labels and axis -line, and "axisMargin" is the space in pixels between axes when there -are two next to each other. Note that you can style the tick labels -with CSS, e.g. to change the color. They have class "tickLabel". - -"borderWidth" is the width of the border around the plot. Set it to 0 -to disable the border. You can also set "borderColor" if you want the -border to have a different color than the grid lines. -"minBorderMargin" controls the default minimum margin around the -border - it's used to make sure that points aren't accidentally -clipped by the canvas edge so by default the value is computed from -the point radius. - -"markings" is used to draw simple lines and rectangular areas in the -background of the plot. You can either specify an array of ranges on -the form { xaxis: { from, to }, yaxis: { from, to } } (with multiple -axes, you can specify coordinates for other axes instead, e.g. as -x2axis/x3axis/...) or with a function that returns such an array given -the axes for the plot in an object as the first parameter. - -You can set the color of markings by specifying "color" in the ranges -object. Here's an example array: - - markings: [ { xaxis: { from: 0, to: 2 }, yaxis: { from: 10, to: 10 }, color: "#bb0000" }, ... ] - -If you leave out one of the values, that value is assumed to go to the -border of the plot. So for example if you only specify { xaxis: { -from: 0, to: 2 } } it means an area that extends from the top to the -bottom of the plot in the x range 0-2. - -A line is drawn if from and to are the same, e.g. - - markings: [ { yaxis: { from: 1, to: 1 } }, ... ] - -would draw a line parallel to the x axis at y = 1. You can control the -line width with "lineWidth" in the range object. - -An example function that makes vertical stripes might look like this: - - markings: function (axes) { - var markings = []; - for (var x = Math.floor(axes.xaxis.min); x < axes.xaxis.max; x += 2) - markings.push({ xaxis: { from: x, to: x + 1 } }); - return markings; - } - - -If you set "clickable" to true, the plot will listen for click events -on the plot area and fire a "plotclick" event on the placeholder with -a position and a nearby data item object as parameters. The coordinates -are available both in the unit of the axes (not in pixels) and in -global screen coordinates. - -Likewise, if you set "hoverable" to true, the plot will listen for -mouse move events on the plot area and fire a "plothover" event with -the same parameters as the "plotclick" event. If "autoHighlight" is -true (the default), nearby data items are highlighted automatically. -If needed, you can disable highlighting and control it yourself with -the highlight/unhighlight plot methods described elsewhere. - -You can use "plotclick" and "plothover" events like this: - - $.plot($("#placeholder"), [ d ], { grid: { clickable: true } }); - - $("#placeholder").bind("plotclick", function (event, pos, item) { - alert("You clicked at " + pos.x + ", " + pos.y); - // axis coordinates for other axes, if present, are in pos.x2, pos.x3, ... - // if you need global screen coordinates, they are pos.pageX, pos.pageY - - if (item) { - highlight(item.series, item.datapoint); - alert("You clicked a point!"); - } - }); - -The item object in this example is either null or a nearby object on the form: - - item: { - datapoint: the point, e.g. [0, 2] - dataIndex: the index of the point in the data array - series: the series object - seriesIndex: the index of the series - pageX, pageY: the global screen coordinates of the point - } - -For instance, if you have specified the data like this - - $.plot($("#placeholder"), [ { label: "Foo", data: [[0, 10], [7, 3]] } ], ...); - -and the mouse is near the point (7, 3), "datapoint" is [7, 3], -"dataIndex" will be 1, "series" is a normalized series object with -among other things the "Foo" label in series.label and the color in -series.color, and "seriesIndex" is 0. Note that plugins and options -that transform the data can shift the indexes from what you specified -in the original data array. - -If you use the above events to update some other information and want -to clear out that info in case the mouse goes away, you'll probably -also need to listen to "mouseout" events on the placeholder div. - -"mouseActiveRadius" specifies how far the mouse can be from an item -and still activate it. If there are two or more points within this -radius, Flot chooses the closest item. For bars, the top-most bar -(from the latest specified data series) is chosen. - -If you want to disable interactivity for a specific data series, you -can set "hoverable" and "clickable" to false in the options for that -series, like this { data: [...], label: "Foo", clickable: false }. - - -Specifying gradients -==================== - -A gradient is specified like this: - - { colors: [ color1, color2, ... ] } - -For instance, you might specify a background on the grid going from -black to gray like this: - - grid: { - backgroundColor: { colors: ["#000", "#999"] } - } - -For the series you can specify the gradient as an object that -specifies the scaling of the brightness and the opacity of the series -color, e.g. - - { colors: [{ opacity: 0.8 }, { brightness: 0.6, opacity: 0.8 } ] } - -where the first color simply has its alpha scaled, whereas the second -is also darkened. For instance, for bars the following makes the bars -gradually disappear, without outline: - - bars: { - show: true, - lineWidth: 0, - fill: true, - fillColor: { colors: [ { opacity: 0.8 }, { opacity: 0.1 } ] } - } - -Flot currently only supports vertical gradients drawn from top to -bottom because that's what works with IE. - - -Plot Methods ------------- - -The Plot object returned from the plot function has some methods you -can call: - - - highlight(series, datapoint) - - Highlight a specific datapoint in the data series. You can either - specify the actual objects, e.g. if you got them from a - "plotclick" event, or you can specify the indices, e.g. - highlight(1, 3) to highlight the fourth point in the second series - (remember, zero-based indexing). - - - - unhighlight(series, datapoint) or unhighlight() - - Remove the highlighting of the point, same parameters as - highlight. - - If you call unhighlight with no parameters, e.g. as - plot.unhighlight(), all current highlights are removed. - - - - setData(data) - - You can use this to reset the data used. Note that axis scaling, - ticks, legend etc. will not be recomputed (use setupGrid() to do - that). You'll probably want to call draw() afterwards. - - You can use this function to speed up redrawing a small plot if - you know that the axes won't change. Put in the new data with - setData(newdata), call draw(), and you're good to go. Note that - for large datasets, almost all the time is consumed in draw() - plotting the data so in this case don't bother. - - - - setupGrid() - - Recalculate and set axis scaling, ticks, legend etc. - - Note that because of the drawing model of the canvas, this - function will immediately redraw (actually reinsert in the DOM) - the labels and the legend, but not the actual tick lines because - they're drawn on the canvas. You need to call draw() to get the - canvas redrawn. - - - draw() - - Redraws the plot canvas. - - - triggerRedrawOverlay() - - Schedules an update of an overlay canvas used for drawing - interactive things like a selection and point highlights. This - is mostly useful for writing plugins. The redraw doesn't happen - immediately, instead a timer is set to catch multiple successive - redraws (e.g. from a mousemove). You can get to the overlay by - setting up a drawOverlay hook. - - - width()/height() - - Gets the width and height of the plotting area inside the grid. - This is smaller than the canvas or placeholder dimensions as some - extra space is needed (e.g. for labels). - - - offset() - - Returns the offset of the plotting area inside the grid relative - to the document, useful for instance for calculating mouse - positions (event.pageX/Y minus this offset is the pixel position - inside the plot). - - - pointOffset({ x: xpos, y: ypos }) - - Returns the calculated offset of the data point at (x, y) in data - space within the placeholder div. If you are working with multiple axes, you - can specify the x and y axis references, e.g. - - o = pointOffset({ x: xpos, y: ypos, xaxis: 2, yaxis: 3 }) - // o.left and o.top now contains the offset within the div - - - resize() - - Tells Flot to resize the drawing canvas to the size of the - placeholder. You need to run setupGrid() and draw() afterwards as - canvas resizing is a destructive operation. This is used - internally by the resize plugin. - - - shutdown() - - Cleans up any event handlers Flot has currently registered. This - is used internally. - - -There are also some members that let you peek inside the internal -workings of Flot which is useful in some cases. Note that if you change -something in the objects returned, you're changing the objects used by -Flot to keep track of its state, so be careful. - - - getData() - - Returns an array of the data series currently used in normalized - form with missing settings filled in according to the global - options. So for instance to find out what color Flot has assigned - to the data series, you could do this: - - var series = plot.getData(); - for (var i = 0; i < series.length; ++i) - alert(series[i].color); - - A notable other interesting field besides color is datapoints - which has a field "points" with the normalized data points in a - flat array (the field "pointsize" is the increment in the flat - array to get to the next point so for a dataset consisting only of - (x,y) pairs it would be 2). - - - getAxes() - - Gets an object with the axes. The axes are returned as the - attributes of the object, so for instance getAxes().xaxis is the - x axis. - - Various things are stuffed inside an axis object, e.g. you could - use getAxes().xaxis.ticks to find out what the ticks are for the - xaxis. Two other useful attributes are p2c and c2p, functions for - transforming from data point space to the canvas plot space and - back. Both returns values that are offset with the plot offset. - Check the Flot source code for the complete set of attributes (or - output an axis with console.log() and inspect it). - - With multiple axes, the extra axes are returned as x2axis, x3axis, - etc., e.g. getAxes().y2axis is the second y axis. You can check - y2axis.used to see whether the axis is associated with any data - points and y2axis.show to see if it is currently shown. - - - getPlaceholder() - - Returns placeholder that the plot was put into. This can be useful - for plugins for adding DOM elements or firing events. - - - getCanvas() - - Returns the canvas used for drawing in case you need to hack on it - yourself. You'll probably need to get the plot offset too. - - - getPlotOffset() - - Gets the offset that the grid has within the canvas as an object - with distances from the canvas edges as "left", "right", "top", - "bottom". I.e., if you draw a circle on the canvas with the center - placed at (left, top), its center will be at the top-most, left - corner of the grid. - - - getOptions() - - Gets the options for the plot, normalized, with default values - filled in. You get a reference to actual values used by Flot, so - if you modify the values in here, Flot will use the new values. - If you change something, you probably have to call draw() or - setupGrid() or triggerRedrawOverlay() to see the change. - - -Hooks -===== - -In addition to the public methods, the Plot object also has some hooks -that can be used to modify the plotting process. You can install a -callback function at various points in the process, the function then -gets access to the internal data structures in Flot. - -Here's an overview of the phases Flot goes through: - - 1. Plugin initialization, parsing options - - 2. Constructing the canvases used for drawing - - 3. Set data: parsing data specification, calculating colors, - copying raw data points into internal format, - normalizing them, finding max/min for axis auto-scaling - - 4. Grid setup: calculating axis spacing, ticks, inserting tick - labels, the legend - - 5. Draw: drawing the grid, drawing each of the series in turn - - 6. Setting up event handling for interactive features - - 7. Responding to events, if any - - 8. Shutdown: this mostly happens in case a plot is overwritten - -Each hook is simply a function which is put in the appropriate array. -You can add them through the "hooks" option, and they are also available -after the plot is constructed as the "hooks" attribute on the returned -plot object, e.g. - - // define a simple draw hook - function hellohook(plot, canvascontext) { alert("hello!"); }; - - // pass it in, in an array since we might want to specify several - var plot = $.plot(placeholder, data, { hooks: { draw: [hellohook] } }); - - // we can now find it again in plot.hooks.draw[0] unless a plugin - // has added other hooks - -The available hooks are described below. All hook callbacks get the -plot object as first parameter. You can find some examples of defined -hooks in the plugins bundled with Flot. - - - processOptions [phase 1] - - function(plot, options) - - Called after Flot has parsed and merged options. Useful in the - instance where customizations beyond simple merging of default - values is needed. A plugin might use it to detect that it has been - enabled and then turn on or off other options. - - - - processRawData [phase 3] - - function(plot, series, data, datapoints) - - Called before Flot copies and normalizes the raw data for the given - series. If the function fills in datapoints.points with normalized - points and sets datapoints.pointsize to the size of the points, - Flot will skip the copying/normalization step for this series. - - In any case, you might be interested in setting datapoints.format, - an array of objects for specifying how a point is normalized and - how it interferes with axis scaling. - - The default format array for points is something along the lines of: - - [ - { x: true, number: true, required: true }, - { y: true, number: true, required: true } - ] - - The first object means that for the first coordinate it should be - taken into account when scaling the x axis, that it must be a - number, and that it is required - so if it is null or cannot be - converted to a number, the whole point will be zeroed out with - nulls. Beyond these you can also specify "defaultValue", a value to - use if the coordinate is null. This is for instance handy for bars - where one can omit the third coordinate (the bottom of the bar) - which then defaults to 0. - - - - processDatapoints [phase 3] - - function(plot, series, datapoints) - - Called after normalization of the given series but before finding - min/max of the data points. This hook is useful for implementing data - transformations. "datapoints" contains the normalized data points in - a flat array as datapoints.points with the size of a single point - given in datapoints.pointsize. Here's a simple transform that - multiplies all y coordinates by 2: - - function multiply(plot, series, datapoints) { - var points = datapoints.points, ps = datapoints.pointsize; - for (var i = 0; i < points.length; i += ps) - points[i + 1] *= 2; - } - - Note that you must leave datapoints in a good condition as Flot - doesn't check it or do any normalization on it afterwards. - - - - drawSeries [phase 5] - - function(plot, canvascontext, series) - - Hook for custom drawing of a single series. Called just before the - standard drawing routine has been called in the loop that draws - each series. - - - - draw [phase 5] - - function(plot, canvascontext) - - Hook for drawing on the canvas. Called after the grid is drawn - (unless it's disabled or grid.aboveData is set) and the series have - been plotted (in case any points, lines or bars have been turned - on). For examples of how to draw things, look at the source code. - - - - bindEvents [phase 6] - - function(plot, eventHolder) - - Called after Flot has setup its event handlers. Should set any - necessary event handlers on eventHolder, a jQuery object with the - canvas, e.g. - - function (plot, eventHolder) { - eventHolder.mousedown(function (e) { - alert("You pressed the mouse at " + e.pageX + " " + e.pageY); - }); - } - - Interesting events include click, mousemove, mouseup/down. You can - use all jQuery events. Usually, the event handlers will update the - state by drawing something (add a drawOverlay hook and call - triggerRedrawOverlay) or firing an externally visible event for - user code. See the crosshair plugin for an example. - - Currently, eventHolder actually contains both the static canvas - used for the plot itself and the overlay canvas used for - interactive features because some versions of IE get the stacking - order wrong. The hook only gets one event, though (either for the - overlay or for the static canvas). - - Note that custom plot events generated by Flot are not generated on - eventHolder, but on the div placeholder supplied as the first - argument to the plot call. You can get that with - plot.getPlaceholder() - that's probably also the one you should use - if you need to fire a custom event. - - - - drawOverlay [phase 7] - - function (plot, canvascontext) - - The drawOverlay hook is used for interactive things that need a - canvas to draw on. The model currently used by Flot works the way - that an extra overlay canvas is positioned on top of the static - canvas. This overlay is cleared and then completely redrawn - whenever something interesting happens. This hook is called when - the overlay canvas is to be redrawn. - - "canvascontext" is the 2D context of the overlay canvas. You can - use this to draw things. You'll most likely need some of the - metrics computed by Flot, e.g. plot.width()/plot.height(). See the - crosshair plugin for an example. - - - - shutdown [phase 8] - - function (plot, eventHolder) - - Run when plot.shutdown() is called, which usually only happens in - case a plot is overwritten by a new plot. If you're writing a - plugin that adds extra DOM elements or event handlers, you should - add a callback to clean up after you. Take a look at the section in - PLUGINS.txt for more info. - - -Plugins -------- - -Plugins extend the functionality of Flot. To use a plugin, simply -include its Javascript file after Flot in the HTML page. - -If you're worried about download size/latency, you can concatenate all -the plugins you use, and Flot itself for that matter, into one big file -(make sure you get the order right), then optionally run it through a -Javascript minifier such as YUI Compressor. - -Here's a brief explanation of how the plugin plumbings work: - -Each plugin registers itself in the global array $.plot.plugins. When -you make a new plot object with $.plot, Flot goes through this array -calling the "init" function of each plugin and merging default options -from the "option" attribute of the plugin. The init function gets a -reference to the plot object created and uses this to register hooks -and add new public methods if needed. - -See the PLUGINS.txt file for details on how to write a plugin. As the -above description hints, it's actually pretty easy. - - -Version number --------------- - -The version number of Flot is available in $.plot.version. |