truncsd

Round a numeric value to the nearest number toward zero with n significant figures.

Usage

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

truncsd( x, n, b )

Rounds a numeric value to the nearest number toward zero with n significant figures.

var v = truncsd( 3.141592653589793, 5, 10 );
// returns 3.1415

v = truncsd( 3.141592653589793, 1, 10 );
// returns 3.0

v = truncsd( 12368.0, 2, 10 );
// returns 12000.0

v = truncsd( 0.0313, 2, 2 );
// returns 0.03125

Examples

var randu = require( '@stdlib/random/base/randu' );
var truncsd = require( '@stdlib/math/base/special/truncsd' );

var x;
var y;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*10000.0) - 5000.0;
    y = truncsd( x, 5, 10 );
    console.log( 'x: %d. Rounded: %d.', x, y );
}

C APIs

Usage

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

stdlib_base_truncsd( x, n, b )

Rounds a numeric value to the nearest number toward negative infinity with n significant figures.

double out = stdlib_base_truncsd( 3.141592653589793, 5, 10 );
// returns 3.1415

The function accepts the following arguments:

x: [in] double input value.
n: [in] int32_t number of significant figures.
b: [in] int32_t base.

double stdlib_base_truncsd( const double x, const int32_t n, const int32_t b );

Examples

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

int main( void ) {
    const double x[] = { -5.0, -3.89, -2.78, -1.67, -0.56, 0.56, 1.67, 2.78, 3.89, 5.0 };
    const int32_t n[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    const int32_t b[] = { 20, 19, 18, 17, 16, 15, 14, 13, 12, 11 };

    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_truncsd( x[ i ], n[ i ], b[ i ] );
        printf( "truncsd(%lf, %d, %d) = %lf\n", x[ i ], n[ i ], b[ i ], v );
    }
}