layer.scaleY < number>

Sets the vertical scale, relative to its transform origin. The default scale is 1. Any number smaller then one will decrease the size and vice versa.
译：设置垂直规模，相对于变换的起源。默认比例是1。 任意数量较小的大小就会减少，反之亦然。

layerA = new Layer
layerA.scaleY = 2