FloatMath.sqrt has been removed from Android SDK 23 #22
Description
The deprecated class has been removed.
"Historically these methods were faster than the equivalent double-based Math methods. On versions of Android with a JIT they became slower and have since been re-implemented to wrap calls to Math. Math should be used in preference.
All methods were removed from the public API in version 23."
http://developer.android.com/reference/android/util/FloatMath.html
The library now needs to use eg. (float) Math.sqrt(pvx_pvx + pvy_pvy);