question: public double distance ( Vector o ) { return Math . sqrt ( NumberConversions . square ( x - o . x ) + NumberConversions . square ( y - o . y ) + NumberConversions . square ( z - o . z ) ) ; }
target:  Get the distance between this vector and another. The value of this method is not cached and uses a costly square-root function, so do not repeatedly call this method to get the vector's magnitude. NaN will be returned if the inner result of the sqrt() function overflows, which will be caused if the distance is too long.