100_035_DoubleAxis

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Double Axis

In previous chapter, options associated to axis are described. But ... some options were not described there. If you want, for some graph types, you can have two different Y axis.

Example:

In this example, on the left axis, there is a scale for the temperature; On the right axis, there is another scale for the rainfall.

Graphs types that can have two axis : line (other will be available soon)

How to define two axis : in the dataset, specify "axis:1" if the data refer to the left axis; specify "axis:2" if the data refer to the right axis.

Example:

 var mydata = {
    labels : ["January","February","March","April","May","June","July"],
    datasets : [
           {
		     fillColor : "rgba(151,187,205,0.5)",
		     strokeColor : "rgba(151,187,205,1)",
		     pointColor : "green",
		     pointstrokeColor : "yellow",
		     data : [60,51,72,64,41,64,37],
		     axis : 2,
		     title : "Rainfall (mm)"
           },
           {
		     fillColor : "rgba(220,220,220,0.5)",
		     strokeColor : "rgba(220,220,220,1)",
		     pointColor : "rgba(220,220,220,1)",
		     pointstrokeColor : "yellow",
		     data : [7,9,13,14,18,21,22],
		     axis : 1,
		     title : "Temperature (degrees Celcius)"
           }
    ]
 }               
 var opt1 = {
  canvasBorders : true,
  graphTitle : "Year 2014",
  legend : true,
  inGraphDataShow : true,
  graphTitleFontSize: 18,
  yAxisRight : true ,
  yAxisUnit : 'Degrees',
  yAxisLabel : 'Temperature',
  yAxisUnit2 : 'mm',
  yAxisLabel2 : 'Rainfall',
  yAxisUnitFontSize: 12,
  yAxisMinimumInterval : 5,
  yAxisMinimumInterval2 : 10,
  graphMin : 0,
  graphMin2 : 0
 }

Attention : the second Y Axis will only be displayed if the option yAxisRight is set to true.

Several options are associated to the second axis; There will not be described here. For a description of them see the corresponding options on the primary axis (same name, without the '2' at the end). Options associated to the second axis :

• scaleOverlay2
• scaleOverride2
• scaleStartValue2
• scaleSteps2
• scaleStepWidth2
• yAxisMinimumInterval2
• yAxisUnit2
• xAxisLabel2

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