Round a numeric value to the nearest power of 10 toward zero.
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> Round a numeric value to the nearest power of 10 toward zero.
``bash`
npm install @stdlib/math-base-special-trunc10
`javascript`
var trunc10 = require( '@stdlib/math-base-special-trunc10' );
#### trunc10( x )
Rounds a numeric value to the nearest power of 10 toward zero.
`javascript
var v = trunc10( -4.2 );
// returns -1.0
v = trunc10( -4.5 );
// returns -1.0
v = trunc10( -4.6 );
// returns -1.0
v = trunc10( 9.99999 );
// returns 1.0
v = trunc10( 9.5 );
// returns 1.0
v = trunc10( 13.0 );
// returns 10.0
v = trunc10( -13.0 );
// returns -10.0
v = trunc10( 0.0 );
// returns 0.0
v = trunc10( -0.0 );
// returns -0.0
v = trunc10( Infinity );
// returns Infinity
v = trunc10( -Infinity );
// returns -Infinity
v = trunc10( NaN );
// returns NaN
`
- The function may not return accurate results for subnormals due to a general loss in precision.
`javascript`
var v = trunc10( 1.0e-323 ); // should return 1.0e-323
// returns 0.0
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var trunc10 = require( '@stdlib/math-base-special-trunc10' );
var opts = {
'dtype': 'float64'
};
var x = uniform( 100, -50.0, 50.0, opts );
logEachMap( 'x: %0.4f. Rounded: %0.4f.', x, trunc10 );
`
*
`c`
#include "stdlib/math/base/special/trunc10.h"
#### stdlib_base_trunc10( x )
Rounds a numeric value to the nearest power of 10 toward zero.
`c`
double y = stdlib_base_trunc10( -4.2 );
// returns -1.0
The function accepts the following arguments:
- x: [in] double input value.
`c`
double stdlib_base_trunc10( const double x );
`c
#include "stdlib/math/base/special/trunc10.h"
#include
int main( void ) {
const double x[] = { 3.14, -3.14, 0.0, 0.0 / 0.0 };
double y;
int i;
for ( i = 0; i < 4; i++ ) {
y = stdlib_base_trunc10( x[ i ] );
printf( "trunc10(%lf) = %lf\n", x[ i ], y );
}
}
`
*
- [@stdlib/math-base/special/ceil10][@stdlib/math/base/special/ceil10]: round a numeric value to the nearest power of 10 toward positive infinity.
- [@stdlib/math-base/special/floor10][@stdlib/math/base/special/floor10]: round a numeric value to the nearest power of 10 toward negative infinity.
- [@stdlib/math-base/special/round10][@stdlib/math/base/special/round10]: round a numeric value to the nearest power of 10 on a linear scale.
- [@stdlib/math-base/special/trunc][@stdlib/math/base/special/trunc]: round a double-precision floating-point number toward zero.
- [@stdlib/math-base/special/trunc2][@stdlib/math/base/special/trunc2]: round a numeric value to the nearest power of two toward zero.
*
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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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/math-base-special-trunc10/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-trunc10/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-trunc10/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-trunc10/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-trunc10/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-trunc10/blob/esm/README.md
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[@stdlib/math/base/special/ceil10]: https://www.npmjs.com/package/@stdlib/math-base-special-ceil10
[@stdlib/math/base/special/floor10]: https://www.npmjs.com/package/@stdlib/math-base-special-floor10
[@stdlib/math/base/special/round10]: https://www.npmjs.com/package/@stdlib/math-base-special-round10
[@stdlib/math/base/special/trunc]: https://www.npmjs.com/package/@stdlib/math-base-special-trunc
[@stdlib/math/base/special/trunc2]: https://www.npmjs.com/package/@stdlib/math-base-special-trunc2