Are Android's DisplayMetrics xdpi and ydpi always equal?

I've been checking the output of the DisplayMetrics 'xdpi' and 'ydpi' on several emulator screen sizes (WVGA & HVGA) and 开发者_高级运维I notice that these values are always equal i.e. metrics.xdpi == metrics.ydpi.

I just wanted to confirm this with folks here? Is it true on any phone the metrics.xdpi will always be equal to the metrics.ydpi value?

Seems, no. For my Samsung Galaxy S (GT-I9000) they are the following (reported by Android):

metrics.xdpi=234.46153
metrics.ydpi=236.27907