bench: refactor random number generation in stats/base/dists/binomial

PR-URL: #4841
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: anandkaranubc

lib/node_modules/@stdlib/stats/base/dists/binomial/cdf/benchmark/benchmark.js

@@ -21,8 +21,9 @@
 // MODULES //
 
 var bench = require( '@stdlib/bench' );
-var ceil = require( '@stdlib/math/base/special/ceil' );
-var randu = require( '@stdlib/random/base/randu' );
+var Float64Array = require( '@stdlib/array/float64' );
+var uniform = require( '@stdlib/random/base/uniform' );
+var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var pkg = require( './../package.json' ).name;
 var cdf = require( './../lib' );
@@ -31,18 +32,26 @@ var cdf = require( './../lib' );
 // MAIN //
 
 bench( pkg, function benchmark( b ) {
+	var len;
 	var n;
 	var p;
 	var x;
 	var y;
 	var i;
 
+	len = 100;
+	x = new Float64Array( len );
+	n = new Float64Array( len );
+	p = new Float64Array( len );
+	for ( i = 0; i < len; i++ ) {
+		x[ i ] = uniform( 0.0, 100.0 );
+		n[ i ] = discreteUniform( 1, 100 );
+		p[ i ] = uniform( 0.0, 1.0 );
+	}
+
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
-		x = randu() * 100.0;
-		n = ceil( randu()*100.0 );
-		p = randu();
-		y = cdf( x, n, p );
+		y = cdf( x[ i % len ], n[ i % len ], p[ i % len ] );
 		if ( isnan( y ) ) {
 			b.fail( 'should not return NaN' );
 		}
@@ -57,6 +66,7 @@ bench( pkg, function benchmark( b ) {
 
 bench( pkg+':factory', function benchmark( b ) {
 	var mycdf;
+	var len;
 	var n;
 	var p;
 	var x;
@@ -66,11 +76,15 @@ bench( pkg+':factory', function benchmark( b ) {
 	n = 80;
 	p = 0.4;
 	mycdf = cdf.factory( n, p );
+	len = 100;
+	x = new Float64Array( len );
+	for ( i = 0; i < len; i++ ) {
+		x[ i ] = uniform( 0.0, 80.0 );
+	}
 
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
-		x = randu() * 80.0;
-		y = mycdf( x );
+		y = mycdf( x[ i % len ] );
 		if ( isnan( y ) ) {
 			b.fail( 'should not return NaN' );
 		}