hypot(3M) — bsd

HYPOT(3M)                            BSD                             HYPOT(3M)



NAME
     hypot, cabs - Euclidean distance, complex absolute value

SYNOPSIS
     #include <math.h>

     double hypot(x,y)
     double x,y;

     double cabs(z)
     struct {double x,y;} z;

DESCRIPTION
     hypot(x,y) and cabs(x,y) return sqrt(x*x+y*y) computed in such a way that
     underflow will not happen, and overflow occurs only if the final result
     deserves it.

     hypot(infinity,v) = hypot(v,infinity) = +infinity for all v, including
     NaN.  math(3M), matherr(3M), sqrt(3M)

NOTES
     As might be expected, hypot(v,NaN) and hypot(NaN,v) are NaN for all
     finite v; with "reserved operand" in place of "NaN".  You might be
     surprised at first to discover that hypot(+infinity,NaN) = +infinity.
     This is intentional; it happens because hypot(infinity,v) = +infinity for
     all v, finite or infinite.  Hence hypot(infinity,v) is independent of v.
     The IEEE NaN is designed to disappear when it turns out to be irrelevant,
     as it does in hypot(infinity,NaN).
Museum
