stdlib-js
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About stdlib...
</summary>
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kernelTan
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
Compute the [tangent][tangent] of a double-precision floating-point number on
[-π/4, π/4].
bash
npm install @stdlib/math-base-special-kernel-tan
javascript
var kernelTan = require( '@stdlib/math-base-special-kernel-tan' );
#### kernelTan( x, y, k )
Computes the [tangent][tangent] of a double-precision floating-point number on [-π/4, π/4].
javascript
var out = kernelTan( 3.141592653589793/4.0, 0.0, 1 );
// returns ~1.0
out = kernelTan( 3.141592653589793/6.0, 0.0, 1 );
// returns ~0.577
out = kernelTan( 0.664, 5.288e-17, 1 );
// returns ~0.783
If k = 1, the function returns tan(x+y). To return the negative inverse -1/tan(x+y), set k = -1.
javascript
var out = kernelTan( 3.141592653589793/4.0, 0.0, -1 );
// returns ~-1.0
If either x or y is NaN, the function returns NaN.
javascript
var out = kernelTan( NaN, 0.0, 1 );
// returns NaN
out = kernelTan( 3.0, NaN, 1 );
// returns NaN
out = kernelTan( NaN, NaN, 1 );
// returns NaN
x and y).
- As components of a [double-double number][double-double-arithmetic], the two [double-precision floating-point numbers][ieee754] x and y must satisfy
ulp stands for [units in the last place][ulp].
javascript
var linspace = require( '@stdlib/array-base-linspace' );
var binomial = require( '@stdlib/random-base-binomial' ).factory;
var PI = require( '@stdlib/constants-float64-pi' );
var kernelTan = require( '@stdlib/math-base-special-kernel-tan' );
var x = linspace( -PI/4.0, PI/4.0, 100 );
var rbinom = binomial( 1, 0.5 );
var descr;
var i;
var k;
for ( i = 0; i < x.length; i++ ) {
k = rbinom();
descr = ( k === 1 ) ? 'tan(%d) = %d' : '-1/tan(%d) = %d';
console.log( descr, x[ i ], kernelTan( x[ i ], 0.0, k ) );
}
c
#include "stdlib/math/base/special/kernel_tan.h"
#### stdlib_base_kernel_tan( x, y, k)
Computes the [tangent][tangent] of a double-precision floating-point number on [-π/4, π/4].
c
double out = stdlib_base_kernel_tan( 3.141592653589793/4.0, 0.0, 1 );
// returns ~1.0
out = stdlib_base_kernel_tan( 3.141592653589793/6.0, 0.0, 1 );
// returns ~0.577
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.
- k: [in] int32_t indicates whether tan(x+y) (if k = 1) or -1/tan(x+y) (if k = -1) is returned.
c
double stdlib_base_kernel_tan( const double x, const double y, const int32_t k );
x and y).
c
#include "stdlib/math/base/special/kernel_tan.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 out;
int i;
for ( i = 0; i < 10; i++ ) {
out = stdlib_base_kernel_tan( x[ i ], 0.0, 1 );
printf( "tan(%lf) = %lf\n", x[ i ], out );
}
}
@stdlib/math-base/special/kernel-cos][@stdlib/math/base/special/kernel-cos]: compute the cosine of a double-precision floating-point number on [-π/4, π/4].
- [@stdlib/math-base/special/kernel-sin][@stdlib/math/base/special/kernel-sin]: compute the sine of a double-precision floating-point number on [-π/4, π/4].
- [@stdlib/math-base/special/tan][@stdlib/math/base/special/tan]: evaluate the tangent of a number.
