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Compute the tangent of a double-precision floating-point number on
[-π/4, π/4].
import kernelTan from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-kernel-tan@esm/index.mjs';Computes the tangent of a double-precision floating-point number on [-π/4, π/4].
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 ~0.783If k = 1, the function returns tan(x+y). To return the negative inverse -1/tan(x+y), set k = -1.
var out = kernelTan( 3.141592653589793/4.0, 0.0, -1 );
// returns ~-1.0If either x or y is NaN, the function returns NaN.
var out = kernelTan( NaN, 0.0, 1 );
// returns NaN
out = kernelTan( 3.0, NaN, 1 );
// returns NaN
out = kernelTan( NaN, NaN, 1 );
// returns NaN-
For increased accuracy, the number for which the tangent should be evaluated can be supplied as a double-double number (i.e., a non-evaluated sum of two double-precision floating-point numbers
xandy). -
As components of a double-double number, the two double-precision floating-point numbers
xandymust satisfy
where
ulpstands for units in the last place.
<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">
import linspace from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-linspace@esm/index.mjs';
var binomial = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-binomial' ).factory;
import PI from 'https://cdn.jsdelivr.net/gh/stdlib-js/constants-float64-pi@esm/index.mjs';
import kernelTan from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-kernel-tan@esm/index.mjs';
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 ) );
}
</script>
</body>
</html>@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: compute the sine of a double-precision floating-point number on [-π/4, π/4].@stdlib/math-base/special/tan: evaluate the tangent of a number.
This package is part of stdlib, a standard library with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
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