feat: add C implementation for @stdlib/stats/base/dists/lognormal/cdf

- Add standalone C implementation using stdlib math functions
- Add native.js binding, header, addon.c, Makefile, binding.gyp
- Add test.native.js, benchmark.native.js and benchmark.js with variable sorting
- Fix max-length bounds in all benchmarks
- Apply correct structure to C APIs section in README

Signed-off-by: Kamal Singh Rautela <e22cseu1624@bennett.edu.in>

Author: rautelaKamal

lib/node_modules/@stdlib/stats/base/dists/lognormal/cdf/README.md

@@ -132,10 +132,24 @@ logEachMap( 'x: %0.4f, µ: %0.4f, σ: %0.4f, F(x;µ,σ): %0.4f', x, mu, sigma, c
 
 <!-- /.examples -->
 
-<!-- C usage documentation. -->
+<!-- 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
@@ -175,23 +189,36 @@ double stdlib_base_dists_lognormal_cdf( const double x, const double mu, const d
 
 <!-- /.notes -->
 
+<!-- C API usage examples. -->
+
 <section class="examples">
 
 ### Examples
 
 ```c
 #include "stdlib/stats/base/dists/lognormal/cdf.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) );
+}
+
 int main( void ) {
+    double x;
+    double mu;
+    double sigma;
     double y;
     int i;
 
     for ( i = 0; i < 25; i++ ) {
-        y = stdlib_base_dists_lognormal_cdf( (double)i, 0.0, 1.0 );
-        printf( "x: %d, cdf: %lf\n", i, y );
+        x = random_uniform( 0.0, 100.0 );
+        mu = random_uniform( -10.0, 10.0 );
+        sigma = random_uniform( 0.1, 10.0 );
+        y = stdlib_base_dists_lognormal_cdf( x, mu, sigma );
+        printf( "x: %lf, mu: %lf, sigma: %lf, F(x;mu,sigma): %lf\n", x, mu, sigma, y );
     }
-    return 0;
 }
 ```
 

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

@@ -34,10 +34,11 @@ var cdf = require( './../lib' );
 bench( pkg, function benchmark( b ) {
 	var sigma;
 	var opts;
+	var len;
 	var mu;
+	var i;
 	var x;
 	var y;
-	var i;
 
 	opts = {
 		'dtype': 'float64'
@@ -46,9 +47,10 @@ bench( pkg, function benchmark( b ) {
 	mu = uniform( 100, -50.0, 50.0, opts );
 	sigma = uniform( 100, EPS, 20.0, opts );
 
+	len = x.length;
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
-		y = cdf( x[ i % x.length ], mu[ i % mu.length ], sigma[ i % sigma.length ] );
+		y = cdf( x[ i % len ], mu[ i % len ], sigma[ i % len ] );
 		if ( isnan( y ) ) {
 			b.fail( 'should not return NaN' );
 		}
@@ -65,10 +67,11 @@ bench( format( '%s:factory', pkg ), function benchmark( b ) {
 	var mycdf;
 	var sigma;
 	var opts;
+	var len;
 	var mu;
+	var i;
 	var x;
 	var y;
-	var i;
 
 	mu = 10.0;
 	sigma = 4.0;
@@ -79,9 +82,10 @@ bench( format( '%s:factory', pkg ), function benchmark( b ) {
 	};
 	x = uniform( 100, 0.0, 50.0, opts );
 
+	len = x.length;
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
-		y = mycdf( x[ i % x.length ] );
+		y = mycdf( x[ i % len ] );
 		if ( isnan( y ) ) {
 			b.fail( 'should not return NaN' );
 		}

lib/node_modules/@stdlib/stats/base/dists/lognormal/cdf/package.json

@@ -13,8 +13,8 @@
       "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
     }
   ],
-  "gypfile": true,
   "main": "./lib",
+  "gypfile": true,
   "directories": {
     "benchmark": "./benchmark",
     "doc": "./docs",