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floor10
Round a numeric value to the nearest power of 10 toward negative infinity.
Installation
npm install @stdlib/mathbasespecialfloor10
Usage
var floor10 = require( '@stdlib/mathbasespecialfloor10' );
floor10( x )
Rounds a numeric
value to the nearest power of 10
toward negative infinity.
var v = floor10( 4.2 );
// returns 10.0
v = floor10( 4.5 );
// returns 10.0
v = floor10( 4.6 );
// returns 10.0
v = floor10( 9.99999 );
// returns 1.0
v = floor10( 9.5 );
// returns 1.0
v = floor10( 13.0 );
// returns 10.0
v = floor10( 13.0 );
// returns 100.0
v = floor10( 0.0 );
// returns 0.0
v = floor10( 0.0 );
// returns 0.0
v = floor10( Infinity );
// returns Infinity
v = floor10( Infinity );
// returns Infinity
v = floor10( NaN );
// returns NaN
Notes

The function may not return accurate results for subnormals due to a general loss in precision.
var v = floor10( 1.0e323 ); // should return 1.0e323 // returns 0.0
Examples
var randu = require( '@stdlib/randombaserandu' );
var floor10 = require( '@stdlib/mathbasespecialfloor10' );
var x;
var v;
var i;
for ( i = 0; i < 100; i++ ) {
x = (randu()*100.0)  50.0;
v = floor10( x );
console.log( 'Value: %d. Rounded: %d.', x, v );
}
See Also

@stdlib/mathbase/special/ceil10
: round a numeric value to the nearest power of 10 toward positive infinity. 
@stdlib/mathbase/special/floor
: round a doubleprecision floatingpoint number toward negative infinity. 
@stdlib/mathbase/special/floor2
: round a numeric value to the nearest power of two toward negative infinity. 
@stdlib/mathbase/special/round10
: round a numeric value to the nearest power of 10 on a linear scale.
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 © 20162024. The Stdlib Authors.