time-to-botec

README.md (5072B)

---

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 @license Apache-2.0
 
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 you may not use this file except in compliance with the License.
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 See the License for the specific language governing permissions and
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 # Words
 
 > Split a [double-precision floating-point number][ieee754] into a higher order word and a lower order word.
 
 <section class="usage">
 
 ## Usage
 
 ```javascript
 var toWords = require( '@stdlib/number/float64/base/to-words' );
 ```
 
 #### toWords( \[out,] x )
 
 Splits a [double-precision floating-point number][ieee754] into a higher order word (unsigned 32-bit `integer`) and a lower order word (unsigned 32-bit `integer`).
 
 ```javascript
 var w = toWords( 3.14e201 );
 // returns [ 1774486211, 2479577218 ]
 ```
 
 By default, the function returns an `array` containing two elements: a higher order word and a lower order word. The lower order word contains the less significant bits, while the higher order word contains the more significant bits and includes the exponent and sign.
 
 ```javascript
 var w = toWords( 3.14e201 );
 // returns [ 1774486211, 2479577218 ]
 
 var high = w[ 0 ];
 // returns 1774486211
 
 var low = w[ 1 ];
 // returns 2479577218
 ```
 
 To avoid unnecessary memory allocation, the function supports providing an output (destination) object.
 
 ```javascript
 var Uint32Array = require( '@stdlib/array/uint32' );
 
 var out = new Uint32Array( 2 );
 
 var w = toWords( out, 3.14e201 );
 // returns <Uint32Array>[ 1774486211, 2479577218 ]
 
 var bool = ( w === out );
 // returns true
 ```
 
 </section>
 
 <!-- /.usage -->
 
 <section class="examples">
 
 ## Examples
 
 <!-- eslint no-undef: "error" -->
 
 ```javascript
 var floor = require( '@stdlib/math/base/special/floor' );
 var randu = require( '@stdlib/random/base/randu' );
 var pow = require( '@stdlib/math/base/special/pow' );
 var toWords = require( '@stdlib/number/float64/base/to-words' );
 
 var frac;
 var exp;
 var w;
 var x;
 var i;
 
 // Generate random numbers and split into words...
 for ( i = 0; i < 100; i++ ) {
     frac = randu() * 10.0;
     exp = -floor( randu()*324.0 );
     x = frac * pow( 10.0, exp );
     w = toWords( x );
     console.log( 'x: %d. higher: %d. lower: %d.', x, w[ 0 ], w[ 1 ] );
 }
 ```
 
 </section>
 
 <!-- /.examples -->
 
 <!-- C interface documentation. -->
 
 * * *
 
 <section class="c">
 
 ## C APIs
 
 <!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
 
 <section class="intro">
 
 </section>
 
 <!-- /.intro -->
 
 <!-- C usage documentation. -->
 
 <section class="usage">
 
 ### Usage
 
 ```c
 #include "stdlib/number/float64/base/to_words.h"
 ```
 
 #### stdlib_base_float64_to_words( x, \*high, \*low )
 
 Splits a double-precision floating-point number into a higher order word and a lower order word.
 
 ```c
 #include <stdint.h>
 
 uint32_t high;
 uint32_t low;
 
 stdlib_base_float64_to_words( 3.14, &high, &low );
 ```
 
 The function accepts the following arguments:
 
 -   **x**: `[in] double` input value.
 -   **high**: `[out] uint32_t*` destination for higher order word.
 -   **low**: `[out] uint32_t*` destination for lower order word.
 
 ```c
 void stdlib_base_float64_to_words( const double x, uint32_t *high, uint32_t *low );
 ```
 
 #### stdlib_base_float64_words_t
 
 An opaque type definition for a union for converting between a double-precision floating-point number and two unsigned 32-bit integers.
 
 ```c
 #include <stdint.h>
 
 stdlib_base_float64_words_t w;
 
 // Assign a double-precision floating-point number:
 w.value = 3.14;
 
 // Extract the high and low words:
 uint32_t high = w.words.high;
 uint32_t low = w.words.low;
 ```
 
 The union has the following members:
 
 -   **value**: `double` double-precision floating-point number.
 
 -   **words**: `struct` struct having the following members:
 
     -   **high**: `uint32_t` higher order word.
     -   **low**: `uint32_t` lower order word.
 
 </section>
 
 <!-- /.usage -->
 
 <!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
 
 <section class="notes">
 
 </section>
 
 <!-- /.notes -->
 
 <!-- C API usage examples. -->
 
 <section class="examples">
 
 ### Examples
 
 ```c
 #include "stdlib/number/float64/base/to_words.h"
 #include <stdint.h>
 #include <stdio.h>
 
 int main() {
     double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 };
 
     uint32_t high;
     uint32_t low;
     int i;
     for ( i = 0; i < 4; i++ ) {
         stdlib_base_float64_to_words( x[ i ], &high, &low );
         printf( "%lf => high: %u, low: %u\n", x[ i ], high, low );
     }
 }
 ```
 
 </section>
 
 <!-- /.examples -->
 
 </section>
 
 <!-- /.c -->
 
 <section class="links">
 
 [ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
 
 </section>
 
 <!-- /.links -->