exp

Natural exponential function.

The natural exponential function is defined as

$$y = e^x$$

where e is Euler's number.

Usage

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

exp( x )

Evaluates the natural exponential function.

var v = exp( 4.0 );
// returns ~54.5982

v = exp( -9.0 );
// returns ~1.234e-4

v = exp( 0.0 );
// returns 1.0

v = exp( NaN );
// returns NaN

Examples

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

var opts = {
    'dtype': 'float64'
};
var x = uniform( 100, -50.0, 50.0, opts );

logEachMap( 'e^%0.4f = %0.4f', x, exp );

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C APIs

Usage

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

stdlib_base_exp( x )

Evaluates the natural exponential function.

double out = stdlib_base_exp( 4.0 );
// returns ~54.5982

out = stdlib_base_exp( -9.0 );
// returns ~1.234e-4

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_exp( const double x );

Examples

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

int main( void ) {
    double x;
    double v;
    int i;

    for ( i = 0; i < 100; i++ ) {
        x = ( (double)rand() / (double)RAND_MAX ) * 100.0;
        v = stdlib_base_exp( x );
        printf( "e^%lf = %lf\n", x, v );
    }
}

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See Also

• @stdlib/math/base/special/exp10: base 10 exponential function.
• @stdlib/math/base/special/exp2: base 2 exponential function.
• @stdlib/math/base/special/expm1: compute exp(x) - 1.
• @stdlib/math/base/special/ln: evaluate the natural logarithm of a double-precision floating-point number.