@jeonkook,
Aligning y-axis for multiple charts can be achieved by setting the margin property. The margin value has to be calculated based on the bounds of y-axis as shown in the code below –
for(var i = 1; i < charts.length; i++) {
charts[i].axisY[0].set("margin", charts[0].axisY[0].bounds.x2 - (charts[i].axisY[0].bounds.x2 - charts[i].axisY[0].bounds.x1));
}
Also, kindly take a look at this updated JSFiddle with the code to align the y-axis for multiple charts.
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Indranil Deo
Team CanvasJS