HYPOT(3M) | Mathematical Library Functions | HYPOT(3M) |

hypot, hypotf, hypotl - Euclidean distance function

c99 [flag... ]file...-lm[library... ] #include <math.h>doublehypot(doublex,doubley);

floathypotf(floatx,floaty);

long doublehypotl(long doublex,long doubley);

These functions compute the length of the square root of
*x*^2 + *y*^2 without undue overflow or underflow.

Upon successful completion, these functions return the length of
the hypotenuse of a right angled triangle with sides of length *x*^2
and *y*^2.

If the correct value would cause overflow, a range error occurs
and **hypot()**, **hypotf()**, and **hypotl()** return the value of
the macro **HUGE_VAL**, **HUGE_VALF**, and **HUGE_VALL**,
respectively.

If *x* or *y* is ±Inf, +Inf is returned even if
one of *x* or *y* is NaN.

If *x* or *y* is NaN and the other is not ±Inf, a
NaN is returned.

These functions will fail if:

**Range Error**

The result overflows.

If the integer expression (**math_errhandling** &
**MATH_ERREXCEPT**) is non-zero, the overflow floating-point exception is
raised.

**hypot**(*x*,*y*), **hypot**(*y*,*x*),
and **hypot**(*x*, −*y*) are equivalent.

**hypot**(*x*, ±0) is equivalent to
**fabs**(*x*).

These functions takes precautions against underflow and overflow during intermediate steps of the computation.

An application wanting to check for exceptions should call
**feclearexcept**(**FE_ALL_EXCEPT**) before calling these functions.
On return, if **fetestexcept**(**FE_INVALID** | **FE_DIVBYZERO** |
**FE_OVERFLOW** | **FE_UNDERFLOW**) is non-zero, an exception has been
raised. An application should either examine the return value or check the
floating point exception flags to detect exceptions.

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE | ATTRIBUTE VALUE |

Interface Stability | Standard |

MT-Level | MT-Safe |

math.h(3HEAD), fabs(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), sqrt(3M), attributes(7), standards(7)

September 1, 2002 | SunOS 5.11 |