feat: add C implementation for stats/base/dists/chisquare/mean

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/README.md

@@ -144,26 +144,27 @@ for ( i = 0; i < 10; i++ ) {
 
 #### stdlib_base_dists_chisquare_mean( k )
 
-Returns the [expected value][expected-value] of a [chi-squared][chisquare-distribution] distribution with degrees of freedom `k`.
+Returns the expected value of a chi-squared distribution with degerees of freedom `k`.
 
 ```c
-double out = stdlib_base_dists_chisquare_mean( 9.0 );
-// returns 9.0
+double y = stdlib_base_dists_chisquare_mean( 9.0 );
+// returns ~9.0
 ```
 
 The function accepts the following arguments:
 
--   **k**: `[in] double` degrees of freedom.
+-   **k**: `[in] double` degrees of freedom
 
 ```c
-double stdlib_base_dists_chisquare_mean( const double k );
+double stdlib_base_dists_chisquare( const double k );
 ```
 
 </section>
 
 <!-- /.usage -->
 
-<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+<!-- C API usage notes. Make sure to keep an empty line after the `section`
+element and another before the `/section` close. -->
 
 <section class="notes">
 
@@ -178,10 +179,6 @@ double stdlib_base_dists_chisquare_mean( const double k );
 ### Examples
 
 ```c
-#include "stdlib/stats/base/dists/chisquare/mean.h"
-#include <stdlib.h>
-#include <stdio.h>
-
 static double random_uniform( const double min, const double max ) {
     double v = (double)rand() / ( (double)RAND_MAX + 1.0 );
     return min + ( v*(max-min) );
@@ -192,10 +189,10 @@ int main( void ) {
     double y;
     int i;
 
-    for ( i = 0; i < 25; i++ ) {
-        k = random_uniform( 0.0, 20.0 );
+    for ( i = 0; i < 10; i++ ) {
+        k = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 20.0 );
         y = stdlib_base_dists_chisquare_mean( k );
-        printf( "k: %lf, E(X;k): %lf\n", k, y );
+        printf( "k: %1f, E(X;k): %lf\n", k, y );
     }
 }
 ```

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/benchmark/benchmark.native.js

@@ -22,11 +22,11 @@
 
 var resolve = require( 'path' ).resolve;
 var bench = require( '@stdlib/bench' );
-var Float64Array = require( '@stdlib/array/float64' );
-var EPS = require( '@stdlib/constants/float64/eps' );
 var uniform = require( '@stdlib/random/base/uniform' );
+var Float64Array = require( '@stdlib/array/float64' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var tryRequire = require( '@stdlib/utils/try-require' );
+var EPS = require( '@stdlib/constants/float64/eps' );
 var pkg = require( './../package.json' ).name;
 
 

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/benchmark/c/benchmark.c

@@ -105,7 +105,7 @@ static double benchmark( void ) {
 
 	t = tic();
 	for ( i = 0; i < ITERATIONS; i++ ) {
-		y = stdlib_base_dists_chisquare_mean( k[ i%100 ] );
+		y = stdlib_base_dists_chisquare_mean( k[ i % 100 ] );
 		if ( y != y ) {
 			printf( "should not return NaN\n" );
 			break;

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/examples/c/example.c

@@ -17,6 +17,7 @@
 */
 
 #include "stdlib/stats/base/dists/chisquare/mean.h"
+#include "stdlib/constants/float64/eps.h"
 #include <stdlib.h>
 #include <stdio.h>
 
@@ -30,9 +31,9 @@ int main( void ) {
 	double y;
 	int i;
 
-	for ( i = 0; i < 25; i++ ) {
-		k = random_uniform( 0.0, 20.0 );
+	for ( i = 0; i < 10; i++ ) {
+		k = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 20.0 );
 		y = stdlib_base_dists_chisquare_mean( k );
-		printf( "k: %lf, E(X;k): %lf\n", k, y );
+		printf( "k: %1f, E(X;k): %lf\n", k, y );
 	}
 }

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/include/stdlib/stats/base/dists/chisquare/mean.h

@@ -27,7 +27,7 @@ extern "C" {
 #endif
 
 /**
-* Returns the expected value of a chi-squared distribution.
+* Returns the expected value of a chi-squared distribution with degerees of freedom `k`.
 */
 double stdlib_base_dists_chisquare_mean( const double k );
 

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/lib/native.js

@@ -28,7 +28,6 @@ var addon = require( './../src/addon.node' );
 /**
 * Returns the expected value of a chi-squared distribution.
 *
-* @private
 * @param {NonNegativeNumber} k - degrees of freedom
 * @returns {NonNegativeNumber} expected value
 *

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/manifest.json

@@ -70,7 +70,8 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/math/base/assert/is-nan"
+        "@stdlib/math/base/assert/is-nan",
+        "@stdlib/constants/float64/eps"
       ]
     }
   ]

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/src/main.c

@@ -20,18 +20,30 @@
 #include "stdlib/math/base/assert/is_nan.h"
 
 /**
-* Returns the expected value of a chi-squared distribution.
+* Returns the expected value of a chi-squared distribution with degerees of freedom `k`.
 *
-* @param x    degrees of freedom
-* @return     expected value
+* @param k    degrees of freedom
+* @returns    evaluated mean
 *
 * @example
-* double y = stdlib_base_chisquare_mean( 9.0 );
-* // returns 9.0
+* double y = stdlib_base_dists_chisquare_mean( 9.0 );
+* // returns ~9.0
+*
+* @example
+* double y = stdlib_base_dists_chisquare_mean( 1.0 );
+* // returns ~1.0
+*
+* @example
+* double y = stdlib_base_dists_chisquare_mean( -0.2 );
+* // returns NaN
+*
+* @example
+* double y = stdlib_base_dists_chisquare_mean( NaN );
+* // returns NaN
 */
 double stdlib_base_dists_chisquare_mean( const double k ) {
 	if ( stdlib_base_is_nan( k ) || k < 0.0 ) {
-		return 0.0/0.0; //NaN
+		return 0.0 / 0.0;
 	}
 	return k;
 }

lib/node_modules/@stdlib/stats/base/dists/chisquare/mean/test/test.native.js

@@ -22,16 +22,11 @@
 
 var resolve = require( 'path' ).resolve;
 var tape = require( 'tape' );
-var tryRequire = require( '@stdlib/utils/try-require' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var tryRequire = require( '@stdlib/utils/try-require' );
 var NINF = require( '@stdlib/constants/float64/ninf' );
 
 
-// FIXTURES //
-
-var data = require( './fixtures/julia/data.json' );
-
-
 // VARIABLES //
 
 var mean = tryRequire( resolve( __dirname, './../lib/native.js' ) );
@@ -40,6 +35,11 @@ var opts = {
 };
 
 
+// FIXTURES //
+
+var data = require( './fixtures/julia/data.json' );
+
+
 // TESTS //
 
 tape( 'main export is a function', opts, function test( t ) {