@stdlib/math-base-special-truncn
v0.3.0
Published
Round a numeric value to the nearest multiple of 10^n toward zero.
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truncn
Round a numeric value to the nearest multiple of 10^n toward zero.
Installation
npm install @stdlib/math-base-special-truncn
Usage
var truncn = require( '@stdlib/math-base-special-truncn' );
truncn( x, n )
Rounds a numeric
value to the nearest multiple of 10^n
toward zero.
// Round a value to 4 decimal places:
var v = truncn( 3.141592653589793, -4 );
// returns 3.1415
// If n = 0, `truncn` behaves like `trunc`:
v = truncn( 3.141592653589793, 0 );
// returns 3.0
// Round a value to the nearest thousand:
v = truncn( 12368.0, 3 );
// returns 12000.0
Notes
- When operating on floating-point numbers in bases other than
2
, rounding to specified digits can be inexact.
Examples
var randu = require( '@stdlib/random-base-randu' );
var truncn = require( '@stdlib/math-base-special-truncn' );
var x;
var n;
var v;
var i;
for ( i = 0; i < 100; i++ ) {
x = (randu()*100.0) - 50.0;
n = truncn( randu()*5.0, 0 );
v = truncn( x, -n );
console.log( 'x: %d. Number of decimals: %d. Rounded: %d.', x, n, v );
}
C APIs
Usage
#include "stdlib/math/base/special/truncn.h"
stdlib_base_truncn( x, n )
Rounds a numeric
value to the nearest multiple of 10^n
toward zero.
double y = stdlib_base_truncn( 3.141592653589793, -4 );
// 3.1415
The function accepts the following arguments:
- x:
[in] double
input value. - n:
[in] int32_t
integer power of 10.
double stdlib_base_truncn( const double x, const int32_t n );
Examples
#include "stdlib/math/base/special/truncn.h"
#include <stdio.h>
int main( void ) {
const double x[] = { 3.141592653589793, -3.141592653589793, 2.731, 3.55555 };
double y;
int i;
for ( i = 0; i < 4; i++ ) {
y = stdlib_base_truncn( x[ i ], -2 );
printf( "truncn(%lf) = %lf\n", x[ i ], y );
}
}
See Also
@stdlib/math-base/special/ceiln
: round a numeric value to the nearest multiple of 10^n toward positive infinity.@stdlib/math-base/special/floorn
: round a double-precision floating-point number to the nearest multiple of 10^n toward negative infinity.@stdlib/math-base/special/roundn
: round a double-precision floating-point number to the nearest multiple of 10^n.@stdlib/math-base/special/trunc
: round a double-precision floating-point number toward zero.@stdlib/math-base/special/truncb
: round a numeric value to the nearest multiple of b^n toward zero.
Notice
This package is part of 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, see the main project repository.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.