Square Root

Compute the principal square root of a double-precision floating-point number.

The principal square root is defined as

$$\sqrt{x^2} = \begin{matrix} x, & \textrm{if}\ x \geq 0\end{matrix}$$

Usage

var sqrt = require( '@stdlib/math/base/special/sqrt' );

sqrt( x )

Computes the principal square root of a double-precision floating-point number.

var v = sqrt( 4.0 );
// returns 2.0

v = sqrt( 9.0 );
// returns 3.0

v = sqrt( 0.0 );
// returns 0.0

v = sqrt( NaN );
// returns NaN

For negative numbers, the principal square root is not defined.

var v = sqrt( -4.0 );
// returns NaN

Examples

var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var logEachMap = require( '@stdlib/console/log-each-map' );
var sqrt = require( '@stdlib/math/base/special/sqrt' );

var opts = {
    'dtype': 'float64'
};
var x = discreteUniform( 100, 0, 100, opts );

logEachMap( 'sqrt(%d) = %0.4f', x, sqrt );

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C APIs

Usage

#include "stdlib/math/base/special/sqrt.h"

stdlib_base_sqrt( x )

Computes the principal square root of a double-precision floating-point number.

double y = stdlib_base_sqrt( 9.0 );
// returns 3.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_sqrt( const double x );

Examples

#include "stdlib/math/base/special/sqrt.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 3.14, 9.0, 0.0, 0.0/0.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_sqrt( x[ i ] );
        printf( "sqrt(%lf) = %lf\n", x[ i ], y );
    }
}

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See Also

• @stdlib/math/base/special/cbrt: compute the cube root of a double-precision floating-point number.
• @stdlib/math/base/special/rsqrt: compute the reciprocal square root of a double-precision floating-point number.