92 lines
1.9 KiB
Markdown
92 lines
1.9 KiB
Markdown
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@license Apache-2.0
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Copyright (c) 2018 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# signbit
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> Return a boolean indicating if the sign bit for a [single-precision floating-point number][ieee754] is on (true) or off (false).
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<section class="usage">
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## Usage
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```javascript
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var signbitf = require( '@stdlib/number/float32/base/signbit' );
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```
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#### signbitf( x )
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Returns a `boolean` indicating if the sign bit for a [single-precision floating-point number][ieee754] is on (`true`) or off (`false`).
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```javascript
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var toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
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var bool = signbitf( toFloat32( 4.0 ) );
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// returns false
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bool = signbitf( toFloat32( -9.14e-34 ) );
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// returns true
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bool = signbitf( 0.0 );
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// returns false
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bool = signbitf( -0.0 );
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// returns true
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```
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</section>
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<!-- /.usage -->
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<section class="examples">
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## Examples
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<!-- eslint no-undef: "error" -->
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```javascript
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var toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
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var randu = require( '@stdlib/random/base/randu' );
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var signbitf = require( '@stdlib/number/float32/base/signbit' );
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var sign;
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var x;
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var i;
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for ( i = 0; i < 100; i++ ) {
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x = (randu()*100.0) - 50.0;
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x = toFloat32( x );
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sign = signbitf( x );
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sign = ( sign ) ? 'true' : 'false';
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console.log( 'x: %d. signbit: %s.', x, sign );
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}
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```
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</section>
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<!-- /.examples -->
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<section class="links">
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[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
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</section>
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<!-- /.links -->
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