fix: correct C implementation to return +Infinity when alpha <= 1, update benchmarks

Author: Planeshifter

lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/benchmark/benchmark.js

@@ -21,8 +21,7 @@
 // MODULES //
 
 var bench = require( '@stdlib/bench' );
-var Float64Array = require( '@stdlib/array/float64' );
-var randu = require( '@stdlib/random/base/randu' );
+var uniform = require( '@stdlib/random/array/uniform' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var pkg = require( './../package.json' ).name;
 var mean = require( './../lib' );
@@ -38,12 +37,8 @@ bench( pkg, function benchmark( b ) {
 	var i;
 
 	len = 100;
-	alpha = new Float64Array( len );
-	beta = new Float64Array( len );
-	for ( i = 0; i < len; i++ ) {
-		alpha[ i ] = ( randu() * 3.5 ) + 1.5; // alpha must be > 1 for mean to be defined
-		beta[ i ] = ( randu() * 9.0 ) + 1.0;
-	}
+	alpha = uniform( len, 1.5, 5.0 ); // alpha must be > 1 for mean to be defined
+	beta = uniform( len, 1.0, 10.0 );
 
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {

lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/benchmark/benchmark.native.js

@@ -22,8 +22,7 @@
 
 var resolve = require( 'path' ).resolve;
 var bench = require( '@stdlib/bench' );
-var Float64Array = require( '@stdlib/array/float64' );
-var randu = require( '@stdlib/random/base/randu' );
+var uniform = require( '@stdlib/random/array/uniform' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var tryRequire = require( '@stdlib/utils/try-require' );
 var pkg = require( './../package.json' ).name;
@@ -47,12 +46,8 @@ bench( pkg + '::native', opts, function benchmark( b ) {
 	var i;
 
 	len = 100;
-	alpha = new Float64Array( len );
-	beta = new Float64Array( len );
-	for ( i = 0; i < len; i++ ) {
-		alpha[ i ] = ( randu() * 3.5 ) + 1.5; // alpha must be > 1 for mean to be defined
-		beta[ i ] = ( randu() * 9.0 ) + 1.0;
-	}
+	alpha = uniform( len, 1.5, 5.0 ); // alpha must be > 1 for mean to be defined
+	beta = uniform( len, 1.0, 10.0 );
 
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {

lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/src/main.c

@@ -31,8 +31,11 @@
 * // returns 2.0
 */
 double stdlib_base_dists_pareto_type1_mean( const double alpha, const double beta ) {
-	if ( stdlib_base_is_nan( alpha ) || stdlib_base_is_nan( beta ) || alpha <= 1.0 || beta <= 0.0 ) {
+	if ( stdlib_base_is_nan( alpha ) || stdlib_base_is_nan( beta ) || alpha <= 0.0 || beta <= 0.0 ) {
 		return 0.0 / 0.0; // NaN
 	}
+	if ( alpha <= 1.0 ) {
+		return 1.0 / 0.0; // +Infinity
+	}
 	return ( alpha * beta ) / ( alpha - 1.0 );
 }