zValueFormatString: String

Defines how z values is formatted before they appear on the indexLabel or toolTip. You can format numbers using this property.

• z value is used only in Bubble chart.

var  chart =  new  CanvasJS.Chart("container",
{
 .
 .
 data: [{
   zValueFormatString: "##.#0 mm",

  },
 ]
 .
 .
});
chart.render();