README.md

kernelSincos

Simultaneously compute the sine and cosine of an angle measured in radians on the interval [-π/4, π/4].

Usage

var kernelSincos = require( '@stdlib/math/base/special/kernel-sincos' );

kernelSincos( x, y, out, stride, offset )

Simultaneously computes the sine and cosine of an angle measured in radians on the interval [-π/4, π/4].

var v = kernelSincos( 0.0, 0.0, [ 0.0, 0.0 ], 1, 0 );
// returns [ ~0.0, ~1.0 ]

v = kernelSincos( 3.141592653589793/2.0, 0.0, [ 0.0, 0.0 ], 1, 0 );
// returns [ ~1.0, ~0.0 ]

v = kernelSincos( -3.141592653589793/6.0, 0.0, [ 0.0, 0.0 ], 1, 0 );
// returns [ ~-0.5, ~0.866 ]

v = kernelSincos( NaN, 0.0, [ 0.0, 0.0 ], 1, 0 );
// returns [ NaN, NaN ]

Examples

var linspace = require( '@stdlib/array/base/linspace' );
var PI = require( '@stdlib/constants/float64/pi' );
var kernelSincos = require( '@stdlib/math/base/special/kernel-sincos' );

var x = linspace( -PI/4.0, PI/4.0, 100 );

var y;
var i;
for ( i = 0; i < x.length; i++ ) {
    y = kernelSincos( x[ i ], 0.0, [ 0.0, 0.0 ], 1, 0 );
    console.log( 'kernelSincos(%d) = [ %d, %d ]', x[ i ], y[ 0 ], y[ 1 ] );
}

---

C APIs

Usage

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

stdlib_base_kernel_sincos( x, y, &sine, &cosine )

Simultaneously computes the sine and cosine of an angle measured in radians on the interval [-π/4, π/4].

double cosine;
double sine;

stdlib_base_kernel_sincos( 0.0, 0.0, &sine, &cosine );

The function accepts the following arguments:

• x: [in] double input value (in radians, assumed to be bounded by ~pi/4 in magnitude).
• y: [in] double tail of x.
• sine: [out] double* destination for the sine.
• cosine: [out] double* destination for the cosine.

void stdlib_base_kernel_sincos( const double x, const double y, double* sine, double* cosine );

Examples

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

int main( void ) {
    const double x[] = { -0.7853981633974483, -0.6108652381980153, -0.4363323129985824, -0.26179938779914946, -0.08726646259971649, 0.08726646259971649, 0.26179938779914935, 0.43633231299858233, 0.6108652381980153, 0.7853981633974483 };

    double cosine;
    double sine;
    int i;
    for ( i = 0; i < 10; i++ ) {
        stdlib_base_kernel_sincos( x[ i ], 0.0, &sine, &cosine );
        printf( "x: %lf => sine: %lf, cosine: %lf\n", x[ i ], sine, cosine );
    }
}