feat: add C implementation for studentized range quantile

lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/README.md

@@ -128,6 +128,106 @@ for ( i = 0; i < 10; i++ ) {
 
 <!-- /.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/stats/base/dists/studentized_range/quantile.h"
+```
+
+#### stdlib_base_dists_studentized_range_quantile( p, r, v, nranges )
+
+Evaluates the quantile function for a studentized range distribution.
+
+```c
+double out = stdlib_base_dists_studentized_range_quantile( 0.5, 3.0, 2.0, 1 );
+// returns ~1.908
+```
+
+The function accepts the following arguments:
+
+-   **p**: `[in] double` input probability.
+-   **r**: `[in] double` sample size for range (must be >= 2).
+-   **v**: `[in] double` degrees of freedom (must be >= 2).
+-   **nranges**: `[in] int32_t` number of groups whose maximum range is considered.
+
+```c
+double stdlib_base_dists_studentized_range_quantile( const double p, const double r, const double v, const int32_t nranges );
+```
+
+</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/stats/base/dists/studentized_range/quantile.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+static double random_double( void ) {
+    int r = rand();
+    return (double)r / ( (double)RAND_MAX + 1.0 );
+}
+
+int main( void ) {
+    double p;
+    double r;
+    double v;
+    double y;
+    int i;
+
+    r = 3.0;
+    v = 5.0;
+
+    for ( i = 0; i < 25; i++ ) {
+        p = random_double();
+        y = stdlib_base_dists_studentized_range_quantile( p, r, v, 1 );
+        printf( "p: %lf, r: %lf, v: %lf, Q(p;r,v): %lf\n", p, r, v, y );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
 <!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
 
 <section class="related">

lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/benchmark/benchmark.native.js

@@ -0,0 +1,65 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var resolve = require( 'path' ).resolve;
+var bench = require( '@stdlib/bench' );
+var randu = require( '@stdlib/random/base/randu' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var tryRequire = require( '@stdlib/utils/try-require' );
+var pkg = require( './../package.json' ).name;
+
+
+// VARIABLES //
+
+var quantile = tryRequire( resolve( __dirname, '..', 'lib', 'native.js' ) );
+var opts = {
+	'skip': ( quantile instanceof Error )
+};
+
+
+// MAIN //
+
+bench( pkg+'::native', opts, function benchmark( b ) {
+	var r;
+	var v;
+	var p;
+	var y;
+	var i;
+
+	r = 3.0;
+	v = 5.0;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		p = randu();
+		y = quantile( p, r, v );
+		if ( isnan( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnan( y ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/benchmark/c/Makefile

@@ -0,0 +1,44 @@
+#/
+# @license Apache-2.0
+#
+# Copyright (c) 2025 The Stdlib Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#/
+
+# TARGETS #
+
+# Run benchmark.
+#
+# This target runs a benchmark.
+
+benchmark: benchmark.out
+	-$< | $( BENCHMARK_FILTER )
+
+.PHONY: benchmark
+
+# Generate a benchmark executable.
+#
+# This target generates a benchmark executable.
+
+benchmark.out: benchmark.c
+	$(QUIET) $(CC) $(CFLAGS) -o $@ $(INCLUDE) -I $(ROOT_DIR)/lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/include $< $(LIBPATH) $(LIBRARIES)
+
+# Clean.
+#
+# This target removes generated files.
+
+clean:
+	$(QUIET) -rm -f *.o *.out
+
+.PHONY: clean

lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/benchmark/c/benchmark.c

@@ -0,0 +1,129 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#include "stdlib/stats/base/dists/studentized_range/quantile.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <sys/time.h>
+
+#define NAME "quantile"
+#define ITERATIONS 1000000
+#define REPEATS 3
+
+/**
+* Prints the TAP version.
+*/
+static void print_version( void ) {
+	printf( "TAP version 13\n" );
+}
+
+/**
+* Prints the TAP summary.
+*
+* @param total     total number of tests
+* @param passing   total number of passing tests
+*/
+static void print_summary( int total, int passing ) {
+	printf( "#\n" );
+	printf( "1..%d\n", total );
+	printf( "# total %d\n", total );
+	printf( "# pass  %d\n", passing );
+	printf( "#\n" );
+	printf( "# ok\n" );
+}
+
+/**
+* Prints benchmarks results.
+*
+* @param elapsed   elapsed time in seconds
+*/
+static void print_results( double elapsed ) {
+	double rate = (double)ITERATIONS / elapsed;
+	printf( "  ---\n" );
+	printf( "  iterations: %d\n", ITERATIONS );
+	printf( "  elapsed: %0.9f\n", elapsed );
+	printf( "  rate: %0.9f\n", rate );
+	printf( "  ...\n" );
+}
+
+/**
+* Returns a clock time.
+*
+* @return clock time
+*/
+static double tic( void ) {
+	struct timeval now;
+	gettimeofday( &now, NULL );
+	return (double)now.tv_sec + (double)now.tv_usec/1.0e6;
+}
+
+/**
+* Generates a pseudorandom double on the interval [0,1].
+*
+* @return pseudorandom double
+*/
+static double rand_double( void ) {
+	int r = rand();
+	return (double)r / ( (double)RAND_MAX + 1.0 );
+}
+
+/**
+* Runs a benchmark.
+*
+* @return elapsed time in seconds
+*/
+static double benchmark( void ) {
+	double elapsed;
+	double p;
+	double y;
+	double t;
+	int i;
+
+	t = tic();
+	for ( i = 0; i < ITERATIONS; i++ ) {
+		p = rand_double();
+		y = stdlib_base_dists_studentized_range_quantile( p, 3.0, 5.0, 1 );
+		if ( y != y ) {
+			printf( "should not return NaN\n" );
+			break;
+		}
+	}
+	elapsed = tic() - t;
+	if ( y != y ) {
+		printf( "should not return NaN\n" );
+	}
+	return elapsed;
+}
+
+/**
+* Main execution sequence.
+*/
+int main( void ) {
+	double elapsed;
+	int i;
+
+	print_version();
+	for ( i = 0; i < REPEATS; i++ ) {
+		printf( "# c::%s\n", NAME );
+		elapsed = benchmark();
+		print_results( elapsed );
+		printf( "ok %d benchmark finished\n", i+1 );
+	}
+	print_summary( REPEATS, REPEATS );
+}

lib/node_modules/@stdlib/stats/base/dists/studentized-range/quantile/binding.gyp

@@ -0,0 +1,21 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [
+        "src/addon.cpp",
+        "src/quantile.c"
+      ],
+      "include_dirs": [
+        "include",
+        "<!@(node -p \"require('@stdlib/utils-library-manifest').include()\")"
+      ],
+      "libraries": [
+        "<!@(node -p \"require('@stdlib/utils-library-manifest').libraries()\")"
+      ],
+      "ldflags": [
+        "<!@(node -p \"require('@stdlib/utils-library-manifest').ldflags()\")"
+      ]
+    }
+  ]
+}