This sample is to rotate the XY-axes label to 90 degrees. 
"labelRotation:90" is defined to rotate the XY-axes label to 90 degrees.
The label can be rotated only if the internal fonts are used.

ā—¸Layout
<verticalAxisRenderers>
	<Axis2DRenderer axis="{vAxis}" labelRotation="90"/>
</verticalAxisRenderers>
<horizontalAxisRenderers>
	<Axis2DRenderer axis="{hAxis}" labelRotation="90" tickPlacement="none"/>
</horizontalAxisRenderers>