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sqrt

Compute the square root of x.

Interface Definition

C interface:

float sqrtf(float x);

double sqrt(double x);

Fortran interface:

RES = SQRTF(X);

RES = SQRT(X);

Parameters

Parameter

Type

Description

Input/Output

x
  • For powf, x is of the single-precision floating-point type.
  • For pow, x is of the double-precision floating-point type.

Floating-point value of the input data

Input

Return Value

  1. If x is greater than 0 and y is a decimal, the result of x raised to the power of y is returned. The value range is r ∈ (0, +INF).
  2. If the input x is ±0, the return value is ±0.
  3. If the input x is +∞, the return value is +∞.
  4. If the input x is NaN, the return value is NaN.

Dependencies

C: "km.h"

Fortran: "km.f03"

Examples

C interface:

    // typical usage 
    double x1 = 1.0, x2 = 2.0, x3 = 3.0, x4 = 4.0; 
    // special handing 
    double a = 0.0, b = INFINITY, c = -INFINITY, d = NAN; 
    // print result 
        printf("sqrt(1.0) = %.15f\n", sqrt(x1)); 
        printf("sqrt(2.0) = %.15f\n", sqrt(x2)); 
        printf("sqrt(3.0) = %.15f\n", sqrt(x3)); 
        printf("sqrt(4.0) = %.15f\n", sqrt(x4)); 
        printf("sqrt(0.0) = %.15f\n", sqrt(a)); 
        printf("sqrt(INFINITY) = %.15f\n", sqrt(b)); 
        printf("sqrt(-INFINITY) = %.15f\n", sqrt(c)); 
        printf("sqrt(NAN) = %.15f\n", sqrt(d)); 
    /* 
     *  sqrt(1.0) = 1.000000000000000 
     *  sqrt(2.0) = 1.414213562373095 
     *  sqrt(3.0) = 1.732050807568877 
     *  sqrt(4.0) = 2.000000000000000 
     *  sqrt(0.0) = 0.000000000000000 
     *  sqrt(INFINITY) = inf 
     *  sqrt(-INFINITY) = nan 
     *  sqrt(NAN) = inf 
     * */

Fortran interface:

    REAL(8) :: X = 3.0 
    PRINT*,  SQRT(X) 
    ! 
    ! OUTPUT 
    !     1.732050807568877 
    !