Compute exp(x) - 1.
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> Compute exp(x) - 1.
``bash`
npm install @stdlib/math-base-special-expm1
`javascript`
var expm1 = require( '@stdlib/math-base-special-expm1' );
#### expm1( x )
Computes exp(x) - 1, where exp(x) is the natural [exponential function][exponential-function].
`javascript
var v = expm1( 0.2 );
// returns ~0.221
v = expm1( -9.0 );
// returns ~-1.0
v = expm1( 0.0 );
// returns 0.0
v = expm1( NaN );
// returns NaN
`
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var expm1 = require( '@stdlib/math-base-special-expm1' );
var opts = {
'dtype': 'float64'
};
var x = uniform( 100, -5.0, 5.0, opts );
logEachMap( 'e^%0.4f - 1 = %0.4f', x, expm1 );
`
*
`c`
#include "stdlib/math/base/special/expm1.h"
#### stdlib_base_expm1( x )
Computes exp(x) - 1, where exp(x) is the natural [exponential function][exponential-function].
`c
double out = stdlib_base_expm1( 0.2 );
// returns ~0.221
out = stdlib_base_expm1( -9.0 );
// returns ~-1.0
`
The function accepts the following arguments:
- x: [in] double input value.
`c`
double stdlib_base_expm1( const double x );
`c
#include "stdlib/math/base/special/expm1.h"
#include
#include
int main( void ) {
double x;
double v;
int i;
for ( i = 0; i < 100; i++ ) {
x = ( ( (double)rand() / (double)RAND_MAX ) * 10.0 ) - 5.0;
v = stdlib_base_expm1( x );
printf( "e^%lf - 1 = %lf\n", x, v );
}
}
`
*
- [@stdlib/math-base/special/exp][@stdlib/math/base/special/exp]: natural exponential function.
- [@stdlib/math-base/special/expm1rel][@stdlib/math/base/special/expm1rel]: relative error exponential.
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, 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.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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---
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[deno-url]: https://github.com/stdlib-js/math-base-special-expm1/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-expm1/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-expm1/tree/umd
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[esm-url]: https://github.com/stdlib-js/math-base-special-expm1/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-expm1/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-expm1/blob/main/branches.md
[exponential-function]: https://en.wikipedia.org/wiki/Exponential_function
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[@stdlib/math/base/special/expm1rel]: https://www.npmjs.com/package/@stdlib/math-base-special-expm1rel