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Prototype: double fmod(double x, double y);
Returns: the floating-point remainder, or 0 if y is 0.
See also: ceil, fabs, floor
The fmod function calculates the floating-point remainder f of (x, y) such
that x = iy + f, where i is an integer, f has the same sign as x, and the
absolute value of f is less than the absolute value of y.
Return Value
The fmod function returns the floating-point remainder. If y is 0, the
function returns 0.