88 lines
1.8 KiB
Markdown
88 lines
1.8 KiB
Markdown
|
<!--
|
||
|
|
|
||
|
|
@license Apache-2.0
|
||
|
|
|
||
|
|
Copyright (c) 2018 The Stdlib Authors.
|
||
|
|
|
||
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
you may not use this file except in compliance with the License.
|
||
|
|
You may obtain a copy of the License at
|
||
|
|
|
||
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
|
||
|
|
Unless required by applicable law or agreed to in writing, software
|
||
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
See the License for the specific language governing permissions and
|
||
|
|
limitations under the License.
|
||
|
|
|
||
|
|
-->
|
||
|
|
|
||
|
|
# signbit
|
||
|
|
|
||
|
|
> Return a boolean indicating if the sign bit for a [double-precision floating-point number][ieee754] is on (true) or off (false).
|
||
|
|
|
||
|
|
<section class="usage">
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
var signbit = require( '@stdlib/number/float64/base/signbit' );
|
||
|
|
```
|
||
|
|
|
||
|
|
#### signbit( x )
|
||
|
|
|
||
|
|
Returns a `boolean` indicating if the sign bit for a [double-precision floating-point number][ieee754] is on (`true`) or off (`false`).
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
var bool = signbit( 4.0 );
|
||
|
|
// returns false
|
||
|
|
|
||
|
|
bool = signbit( -9.14e-307 );
|
||
|
|
// returns true
|
||
|
|
|
||
|
|
bool = signbit( 0.0 );
|
||
|
|
// returns false
|
||
|
|
|
||
|
|
bool = signbit( -0.0 );
|
||
|
|
// returns true
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
<!-- /.usage -->
|
||
|
|
|
||
|
|
<section class="examples">
|
||
|
|
|
||
|
|
## Examples
|
||
|
|
|
||
|
|
<!-- eslint no-undef: "error" -->
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
var randu = require( '@stdlib/random/base/randu' );
|
||
|
|
var signbit = require( '@stdlib/number/float64/base/signbit' );
|
||
|
|
|
||
|
|
var sign;
|
||
|
|
var x;
|
||
|
|
var i;
|
||
|
|
|
||
|
|
for ( i = 0; i < 100; i++ ) {
|
||
|
|
x = ( randu()*100.0 ) - 50.0;
|
||
|
|
sign = signbit( x );
|
||
|
|
sign = ( sign ) ? 'true' : 'false';
|
||
|
|
console.log( 'x: %d. signbit: %s.', x, sign );
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
<!-- /.examples -->
|
||
|
|
|
||
|
|
<section class="links">
|
||
|
|
|
||
|
|
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
<!-- /.links -->
|