In the section on mathematical functions the following is given for atan2: atan2(x, y) inverse tangent of a/x
I believe the correct version should either be: atan2(y, x) inverse tangent of y/x or atan2(x, y) inverse tangent of x/y I beleive the documentation was also wrong for 7.2 where it was: atan2(x, y) inverse tangent of y/x The postgres functions seems to be the same as glibc function of the same name when has the following man information: double atan2(double y, double x); DESCRIPTION The atan2() function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster