About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 17 years
old) and has a wealth of features making it an ideal
choice to use for showing charts on your website.
Download
Get the latest version of RGraph (version 6.20, 1st December 2024) from
the download page. You can read the changelog here. There's also older versions available,
minified files and links to cdnjs.com hosted libraries.
License
RGraph can be used for free under the GPL or if
that doesn't suit your situation there's an
inexpensive (£129) commercial license available.The drawing API Y-axis object API reference
The y-axis
object allows you to have extra Y axes in your chart. Formerly
this was an independent function but it's now been
converted to a drawing api
object. This means that it's easier to use and
has added interactivity options - such as mousemove
and click
events and tooltips.
Usage example
<script> bar = new RGraph.Bar({ id: 'cvs', data: [[1,2,8],[3,8,7],[9,6,5],[3,5,8],[5,6,6],[1,5,8],[4,8,6]], options: { backgroundGridVlines: false, backgroundGridBorder: false, marginInner: 5, xaxis: false, yaxis: false, xaxisLabels: ['Mar','Apr','May','Jun','Jul','Aug','Sep'], yaxisScale: false, marginLeft: 195, marginTop: 35, colors: [ 'Gradient(green:#0c0)', 'Gradient(red:#c00)', 'Gradient(blue:#00c)' ], tooltips: [ 'James','Jenna','Karl', 'James','Jenna','Karl', 'James','Jenna','Karl', 'James','Jenna','Karl', 'James','Jenna','Karl', 'James','Jenna','Karl', 'James','Jenna','Karl' ], key: ['James','Jenna','Karl'], keyPosition: 'margin', marginInner: 10, textSize: 16 } }).wave(); new RGraph.Drawing.YAxis({ id: 'cvs', x: bar.marginLeft, options: { marginTop: 35, yaxisScaleMax: bar.scale2.max * 2, yaxisScaleDecimals: 1, textColor: 'blue', textSize: 16, yaxisColor: ['blue'], tooltips: 'Moisture measured by the MET office', tooltipsCss: { backgroundColor: 'black', color: 'white' } } }).draw(); new RGraph.Drawing.YAxis({ id: 'cvs', x: bar.marginLeft - 70, options: { marginTop: 35, yaxisScaleMax: bar.scale2.max * 5, yaxisScaleDecimals: 1, textColor: 'red', textSize: 16, yaxisColor: ['red'], tooltips: 'Sunshine measured by the MET office', tooltipsCss: { backgroundColor: 'black', color: 'white' } } }).draw(); new RGraph.Drawing.YAxis({ id: 'cvs', x: bar.marginLeft - 140, options: { marginTop: 35, yaxisScaleMax: bar.scale2.max, yaxisScaleDecimals: 1, tooltips: ['Rainfall measured by the MET office'], tooltipsCss: { backgroundColor: 'black', color: 'white' }, yaxisColor: ['green'], textColor: 'green', textSize: 16 } }).draw(); </script>
Properties
- Y-axis properties
- Margin properties
- Other label properties
- Interactive features properties
- Miscellaneous properties
Y-axis properties
Name: yaxisTickmarksCount
Description:
This allows you to stipulate how many
y-axis
tickmarks there are.Default: null (related to how many labels there are)
Name: yaxisTickmarksLastTop
Description:
Whether the top-most tickmark is drawn.
Default: null (displayed if the
x-axis
position warrants it)Name: yaxisTickmarksLastBottom
Description:
Whether the bottom-most tickmark is drawn.
Default: null (displayed if the
x-axis
position warrants it)Name: yaxisLabelsCount
Description:
A value that controls how many Y labels there are. This value could formerly be either 1/3/5/10 however now it can be any number.
Default: 5
Name: yaxisLabelsSpecific
Description:
You can use this option to give your own Y labels (eg
['Low', 'Medium', 'High']
. Note: Since March 2013 you may now need to add an extra (optionally) empty element to the array of labels to achieve your desired result.Default: null
Name: yaxisLabelsPosition
Description:
This controls how the specific labels are positioned on the
y-axis
. It has no effect on a scale.Default: edge
Name: yaxisLabelsOffsetx
Description:
This allows you finer-grained control in the horizontal direction over the Y label positioning if you need it.
Default: 0
Name: yaxisLabelsOffsety
Description:
This allows you finer-grained control in the vertical direction over the Y label positioning if you need it.
Default: 0
Name: yaxisLabelsClass
Description:
This property allows you to add your own
css
class to the y-axis
labels which you can then use for styling purposes or to make retrieving the span
tags easier (the dom
elements). If you inspect the labels in your browser's javascript
console (you will first need to enable the textAccessiblePointerevents
property) you will be able to see the other css
classes that are assigned to the labels.Default: [none]
Name: yaxisTitleSize
Description:
This allows you to specify a size for the
y-axis
title.Default: null
Name: yaxisTitleFont
Description:
This allows you to specify a font for the
y-axis
title.Default: null
Name: yaxisTitleBold
Description:
This controls whether the
y-axis
title is bold or not.Default: null
Name: yaxisTitleItalic
Description:
This controls whether the
y-axis
title is italic or not.Default: null
Name: yaxisTitlePos
Description:
This is multiplied with the margin to give the position of the
y-axis
title.Default: 0.25
Name: yaxisTitleOffsetx
Description:
The pixel offset that's added to the
y-axis
titles X coordinate.Default: 0
Name: yaxisTitleOffsety
Description:
The pixel offset that's added to the
y-axis
titles Y coordinate.Default: 0
Name: yaxisTitleX
Description:
By giving this you can specifically set the X position of the
y-axis
title.Default: null
Name: yaxisTitleY
Description:
By giving this you can specifically set the Y position of the
y-axis
title.Default: null
Name: yaxisScaleUnitsPre
Description:
The units that the
y-axis
is measured in. This string is displayed before the actual number, allowing you to specify values such as "$50".Default: none
Name: yaxisScaleUnitsPost
Description:
The units that the
y-axis
is measured in. This string is displayed after the actual number, allowing you to specify values such as "50ms".Default: none
Name: yaxisScaleMax
Description:
The optional maximum Y scale value. If not specified then it will be calculated.
Default: null (It's calculated)
Name: yaxisScaleMin
Description:
The optional minimum Y scale value. If not specified then it will be 0.
Default: 0
Name: yaxisScaleFormatter
Description:
To allow thoroughly custom formats of numbers in the scale, you can use this option to specify a function that is used by RGraph to format numbers. This function should handle ALL of the formatting. Eg:
function myFormatter(opt) { var num = Number(opt.number) * 5; return String(num) } obj.set('yaxisScaleFormatter', myFormatter);
Default: null
Name: yaxisScaleRound
Description:
Whether to round the scale up. eg A maximum value of 59 results in scale to 100.
Default: false
Margin properties
Name: marginTop
Description:
The top margin of the axis. This can be the same or different to the chart.
Default: 35
Other label properties
Name: textAccessible
Description:
A new feature in 2016 that allows you to use
dom
text in place of canvas
text. It makes for much higher quality text that you can also select if desired (for copy/paste operations). It won't fit all situations and you can read more about the DOM text feature here. A good way to control borders/margins/padding etc is not to set them on the canvas
but to wrap the canvas
in a div
and set them on that like this:
<div style="margin-left: 50px; display: inline-block"> <canvas id="cvs" width="650" height="250"></canvas> </div>
Default: false
Name: text
Description:
This allows you to add custom text to your chart if you want to. There's a dedicated page that describes this option here.
Default: null
Interactive features properties
Name: tooltips
Description:
This can be an array of tooltips (only the first element is used) that are shown when the axis is clicked on.
Default: null
Name: tooltipsEvent
Description:
This is the event that triggers the tooltips. It can be either
click
or mousemove
.Default: click
Name: tooltipsEffect
Description:
The effect used for showing tooltips. Can be either
fade
or none
.Default: fade
Name: tooltipsCssClass
Description:
This is the name of the
css
class the chart uses.Default: RGraph_tooltip
Name: tooltipsOverride
Description:
If you wish to handle showing tooltips yourself, this should be a function object which does just that. There's more information on the tooltips documentation page.
Default: null
Name: tooltipsPersistent
Description:
If you want the tooltips to persist after a click (ie they don't disappear) then you can set this property to
true
to get this behaviour. Keep in mind that if you have a lot of bars/segments/points/etc then it's possible for the chart to become quite crowded. If you need to subsequently clear all of the tooltips there's an api
function available to do that for you and it's called: RGraph.tooltip.persistent.clear()
If you want to access any (or all) of the tooltip div
tags then you can do so using the RGraph.tooltip.persistent
object. This option works when you have the tooltipsEvent
property set to mousemove
Default: false
Name: tooltipsNohideonclear
Description:
Not an option that you'll need particularly often, if at all. Setting this to true means that when you call the
RGraph.clear
api
function the tooltip DOES NOT get hidden.Default: false
Name: tooltipsFormattedPoint
Description:
When using formatted tooltip strings this is used as the point when using the
%{value_formatted}
option.Default: .
Name: tooltipsFormattedThousand
Description:
When using formatted tooltip strings this is used as the thousand separator when using the
%{value_formatted}
option.Default: ,
Name: tooltipsFormattedDecimals
Description:
When using formatted tooltip strings this specifies the number of decimals when using the
%{value_formatted}
option.Default: 0
Name: tooltipsFormattedUnitsPre
Description:
When using formatted tooltip strings these units are prepended to the number when using the
%{value_formatted}
option.Default: (an empty string)
Name: tooltipsFormattedUnitsPost
Description:
When using formatted tooltip strings these units are appended to the number when using the
%{value_formatted}
option.Default: (an empty string)
Name: tooltipsFormattedListType
Description:
With this property you can switch between an unordered list (the default) and an ordered list. Possible values are
ul
and ol
.Default: ul
Name: tooltipsFormattedListItems
Description:
This should be a two-dimensional array of the list items that are to be shown for all of the tooltips. An example of this property is:
tooltipsFormattedListItems: [ ['Bill','Jerry','Berty'], // First tooltip ['Gill','Carrie','Lucy'], // Second tooltip ['Pob','Nobby','Hilda'] // Third tooltip ]You can use
css
to style this list - for example:.RGraph_tooltip ul#rgraph_formatted_tooltips_list li { text-align: left; color: yellow; }
Default: null
Name: tooltipsFormattedTableHeaders
Description:
When showing a table in the tooltips this can be an array of headers for the table. These are added to the tooltip using
th
tags.Default: null
Name: tooltipsFormattedTableData
Description:
This is the data that is added to the table. This is a 3-dimensional array so it's easy to make a mistake. See the example, copy the code from it and then modify it suit. You'll create fewer bugs this way.
Default: null)
Name: tooltipsPointer
Description:
By default the tooltips have a small triangular pointer that points to the shape that was clicked on. You can turn this off with this property.
Default: true
Name: tooltipsPointerCss
Description:
If you want any
css
values applied to the tooltips pointer (a css
border, for example) then specify an object containing those values to this property. For example: tooltips: { borderLeft: 'gray 2px solid', borderBottom: 'gray 2px solid' }
Default: null
Name: tooltipsPointerOffsetx
Description:
This allows you to adjust the vertical position of the tooltips pointer.
Default: 0
Name: tooltipsPointerOffsety
Description:
This allows you to adjust the vertical position of the tooltips pointer (for example, if you add a border you may need to move it down slightly).
Default: 0
Name: tooltipsPositionStatic
Description:
The new default (as of August 2020) is for tooltips to be positioned statically and not be dependent on the mouse position. If you don't want this for whatever reason, you can disable it with this setting. When you set it to
false
tooltips are positioned next to the mouse pointer.Default: true
Name: tooltipsCss
Description:
If you want to specify some
css
that gets applied to all of the tooltips, but don't want to use the RGraph.tooltips.style
object (which gets applied to all of the tooltips on the page for every chart) you can use this property to give some per-object css
for the tooltips. These are css
styles that get applied to all of the tooltips for the specific object only. It should look like this:tooltipsCss: { fontFamily: 'Verdana', fontSize: '20pt' }
Default: null
Miscellaneous properties
Methods
obj.get(name)
An accessor that you can use to retrieve the values of properties.
obj.set(name, value)
An accessor that you can use to set the values of properties.
obj.getShape(event)
This method makes it easy to get hold of the
y-axis
object when it has been clicked on or hovered over.
It returns an object which has the following indexes available:
object |
The chart object. |
x |
The X coordinate of the y-axis . |
y |
The Y coordinate of the y-axis . |
width |
The width of the y-axis (this includes the label area)(. |
height |
The height of the y-axis . |
dataset |
As there's only ever one element this is always zero. |
index |
As there's only ever one element this is always zero. |
sequentialIndex |
As there's only ever one element this is always zero. |
tooltip |
If a tooltip is associated with the y-axis object this will be it.id:
strings are expanded for you (where the tooltip text is retrieved from the html
tag with the matching ID).
|
<script>
yaxis.canvas.onclick = function (e)
{
RGraph.redraw();
var canvas = e.target,
obj = canvas.__object__,
shape = obj.getShape(e);
if (shape) {
// Highlight the main body of the Background object.
obj.path(
'lw 10 b r % % % % s black f rgba(255,0,0,0.25)',
shape.x, shape.y, shape.width, shape.height
);
}
}
</script>
obj.on(event, function)
This method can be used to set an event listener on an object.
It operates similarly to the jquery
on
function.
The first argument is the event that you wish to attach to and the second
is the handler function. For example:
obj.on('draw', function (obj)
{
// Put your event code here
});
The function is useful if you use method chaining when creating your charts:
obj = new RGraph.Drawing.YAxis({ id: 'cvs', x: 25, options: { } }).on('draw', function (obj) { // Put your draw event code here }).on('click', function (e, shape) { // Handle the click event }).draw();
obj.exec(function)