stdlib-js
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About stdlib...
</summary>
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powm1
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Evaluate
bˣ - 1.
b is close to 1 and/or x is small, this implementation is more accurate than naively computing bˣ minus 1.
bash
npm install @stdlib/math-base-special-powm1
javascript
var powm1 = require( '@stdlib/math-base-special-powm1' );
#### powm1( b, x )
Evaluates bˣ - 1.
javascript
var y = powm1( 2.0, 3.0 );
// returns 7.0
y = powm1( 4.0, 0.5 );
// returns 1.0
y = powm1( 0.0, 100.0 );
// returns -1.0
y = powm1( 100.0, 0.0 );
// returns 0.0
y = powm1( 0.0, 0.0 );
// returns 0.0
y = powm1( 3.141592653589793, 5.0 );
// returns ~305.0197
y = powm1( NaN, 3.0 );
// returns NaN
y = powm1( 5.0, NaN );
// returns NaN
javascript
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var powm1 = require( '@stdlib/math-base-special-powm1' );
var b;
var x;
var y;
var i;
for ( i = 0; i < 100; i++ ) {
b = round( randu()*10.0 );
x = round( randu()*10.0 ) - 5.0;
y = powm1( b, x );
console.log( '%d^%d - 1 = %d', b, x, y );
}
c
#include "stdlib/math/base/special/powm1.h"
#### stdlib_base_powm1( base, exponent )
Evaluates bˣ - 1.
c
double out = stdlib_base_powm1( 3.141592653589793, 5.0 );
// returns ~305.0197
out = stdlib_base_powm1( 4.0, 0.5 );
// returns 1.0
The function accepts the following arguments:
- base: [in] double base.
- exponent: [in] double exponent.
c
double stdlib_base_powm1( const double base, const double exponent );
c
#include "stdlib/math/base/special/powm1.h"
#include <stdlib.h>
#include <stdio.h>
int main( void ) {
double out;
double b;
double x;
int i;
for ( i = 0; i < 100; i++ ) {
b = ( ( (double)rand() / (double)RAND_MAX ) * 10.0 );
x = ( ( (double)rand() / (double)RAND_MAX ) * 10.0 ) - 5.0;
out = stdlib_base_powm1( b, x );
printf( "powm1(%lf, %lf) = %lf\n", b, x, out );
}
}
@stdlib/math-base/special/pow][@stdlib/math/base/special/pow]: exponential function.
