feat: add C implementation for blas/base/zaxpy

lib/node_modules/@stdlib/blas/base/zaxpy/README.md

@@ -51,9 +51,9 @@ The function has the following parameters:
 -   **N**: number of indexed elements.
 -   **alpha**: scalar [`Complex128`][@stdlib/complex/float64/ctor] constant.
 -   **x**: first input [`Complex128Array`][@stdlib/array/complex128].
--   **strideX**: index increment for `x`.
+-   **strideX**: stride length for `x`.
 -   **y**: second input [`Complex128Array`][@stdlib/array/complex128].
--   **strideY**: index increment for `y`.
+-   **strideY**: stride length for `y`.
 
 The `N` and stride parameters determine how values from `x` are scaled by `alpha` and added to `y`. For example, to scale every other value in `x` by `alpha` and add the result to every other value of `y`,
 
@@ -137,6 +137,7 @@ zaxpy.ndarray( 3, alpha, x, 1, 1, y, 1, 1 );
 ## Notes
 
 -   If `N <= 0`, both functions return `y` unchanged.
+-   If `alpha === 0`, both functions return `y` unchanged.
 -   `zaxpy()` corresponds to the [BLAS][blas] level 1 function [`zaxpy`][zaxpy].
 
 </section>
@@ -171,6 +172,14 @@ var alpha = new Complex128( 2.0, 2.0 );
 // Scale values from `x` by `alpha` and add the result to `y`:
 zaxpy( x.length, alpha, x, 1, y, 1 );
 
+// Print the results:
+logEach( '(%s)*(%s) + (%s) = %s', alpha, x, yc, y );
+
+yc = zcopy( y.length, y, 1, zeros( y.length, 'complex128' ), 1 );
+
+// Scale values from `x` by `alpha` and add the result to `y` using alternative indexing semantics:
+zaxpy.ndarray( x.length, alpha, x, 1, 0, y, 1, 0 );
+
 // Print the results:
 logEach( '(%s)*(%s) + (%s) = %s', alpha, x, yc, y );
 ```
@@ -179,6 +188,152 @@ logEach( '(%s)*(%s) + (%s) = %s', alpha, x, yc, y );
 
 <!-- /.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/blas/base/zaxpy.h"
+```
+
+#### c_zaxpy( N, alpha, \*X, strideX, \*Y, strideY )
+
+Scales values from `X` by `alpha` and adds the result to `Y`.
+
+```c
+#include "stdlib/complex/float32/ctor.h"
+
+float x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };
+float y[] = { -1.0, -2.0, -3.0, -4.0, -5.0, -6.0, -7.0, -8.0 };
+const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );
+
+c_zaxpy( 4, alpha, (void *)x, 1, (void *)y, 1 );
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **alpha**: `[in] stdlib_complex128_t` scalar constant.
+-   **X**: `[in] void*` input array.
+-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
+-   **Y**: `[inout] void*` output array.
+-   **strideY**: `[in] CBLAS_INT` stride length for `Y`.
+
+```c
+void c_zaxpy( const CBLAS_INT N, const stdlib_complex128_t alpha, const void *x, const CBLAS_INT strideX, void *y, const CBLAS_INT strideY );
+```
+
+#### c_zaxpy_ndarray( N, alpha, \*X, strideX, offsetX, \*Y, strideY, offsetY )
+
+Scales values from `X` by `alpha` and adds the result to `Y` using alternative indexing semantics.
+
+```c
+#include "stdlib/complex/float32/ctor.h"
+
+float x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };
+float y[] = { -1.0, -2.0, -3.0, -4.0, -5.0, -6.0, -7.0, -8.0 };
+const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );
+
+c_zaxpy_ndarray( 4, alpha, (void *)x, 1, 0, (void *)y, 1, 0 );
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **alpha**: `[in] stdlib_complex128_t` scalar constant.
+-   **X**: `[in] void*` input array.
+-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
+-   **offsetX**: `[in] CBLAS_INT` starting index for `X`.
+-   **Y**: `[inout] void*` output array.
+-   **strideY**: `[in] CBLAS_INT` stride length for `Y`.
+-   **offsetY**: `[in] CBLAS_INT` starting index for `Y`.
+
+```c
+void c_zaxpy_ndarray( const CBLAS_INT N, const stdlib_complex128_t alpha, const void *x, const CBLAS_INT strideX, const CBLAS_INT offsetX, void *y, const CBLAS_INT strideY, const CBLAS_INT offsetY );
+```
+
+</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/blas/base/zaxpy.h"
+#include "stdlib/complex/float32/ctor.h"
+#include <stdio.h>
+
+int main( void ) {
+    // Create strided arrays:
+    double x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };
+    double y[] = { 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 };
+
+    // Create a complex scalar:
+    const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );
+
+    // Specify the number of elements:
+    const int N = 4;
+
+    // Specify stride lengths:
+    const int strideX = 1;
+    const int strideY = 1;
+
+    // Scale values from `x` by `alpha` and add the result to `y`:
+    c_zaxpy( N, alpha, (void *)x, strideX, (void *)y, strideY );
+
+    // Print the result:
+    for ( int i = 0; i < N; i++ ) {
+        printf( "zaxpy[ %i ] = %lf + %lfj\n", i, y[ i * 2 ], y[ ( i * 2 ) + 1 ] );
+    }
+
+    // Scale values from `x` by `alpha` and add the result to `y` using alternative indexing semantics:
+    c_zaxpy_ndarray( N, alpha, (void *)x, strideX, 0, (void *)y, strideY, 0 );
+
+    // Print the result:
+    for ( int i = 0; i < N; i++ ) {
+        printf( "zaxpy[ %i ] = %lf + %lfj\n", i, y[ i * 2 ], y[ ( i * 2 ) + 1 ] );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
 <!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
 
 <section class="related">
@@ -193,7 +348,7 @@ logEach( '(%s)*(%s) + (%s) = %s', alpha, x, yc, y );
 
 [blas]: http://www.netlib.org/blas
 
-[zaxpy]: https://www.netlib.org/lapack/explore-html/d5/d4b/group__axpy_ga0b7bac1f4d42514074a48f14f5f9caa0.html#ga0b7bac1f4d42514074a48f14f5f9caa0
+[zaxpy]: https://www.netlib.org/lapack/explore-html/d5/d4b/group__axpy_gaf603daa00d5c723d0e409d9b2d011bf4.html
 
 [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
 

lib/node_modules/@stdlib/blas/base/zaxpy/benchmark/c/Makefile

@@ -0,0 +1,146 @@
+#/
+# @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.
+#/
+
+# VARIABLES #
+
+ifndef VERBOSE
+	QUIET := @
+else
+	QUIET :=
+endif
+
+# Determine the OS ([1][1], [2][2]).
+#
+# [1]: https://en.wikipedia.org/wiki/Uname#Examples
+# [2]: http://stackoverflow.com/a/27776822/2225624
+OS ?= $(shell uname)
+ifneq (, $(findstring MINGW,$(OS)))
+	OS := WINNT
+else
+ifneq (, $(findstring MSYS,$(OS)))
+	OS := WINNT
+else
+ifneq (, $(findstring CYGWIN,$(OS)))
+	OS := WINNT
+else
+ifneq (, $(findstring Windows_NT,$(OS)))
+	OS := WINNT
+endif
+endif
+endif
+endif
+
+# Define the program used for compiling C source files:
+ifdef C_COMPILER
+	CC := $(C_COMPILER)
+else
+	CC := gcc
+endif
+
+# Define the command-line options when compiling C files:
+CFLAGS ?= \
+	-std=c99 \
+	-O3 \
+	-Wall \
+	-pedantic
+
+# Determine whether to generate position independent code ([1][1], [2][2]).
+#
+# [1]: https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#Code-Gen-Options
+# [2]: http://stackoverflow.com/questions/5311515/gcc-fpic-option
+ifeq ($(OS), WINNT)
+	fPIC ?=
+else
+	fPIC ?= -fPIC
+endif
+
+# List of includes (e.g., `-I /foo/bar -I /beep/boop/include`):
+INCLUDE ?=
+
+# List of source files:
+SOURCE_FILES ?=
+
+# List of libraries (e.g., `-lopenblas -lpthread`):
+LIBRARIES ?=
+
+# List of library paths (e.g., `-L /foo/bar -L /beep/boop`):
+LIBPATH ?=
+
+# List of C targets:
+c_targets := benchmark.length.out
+
+
+# RULES #
+
+#/
+# Compiles source files.
+#
+# @param {string} [C_COMPILER] - C compiler (e.g., `gcc`)
+# @param {string} [CFLAGS] - C compiler options
+# @param {(string|void)} [fPIC] - compiler flag determining whether to generate position independent code (e.g., `-fPIC`)
+# @param {string} [INCLUDE] - list of includes (e.g., `-I /foo/bar -I /beep/boop/include`)
+# @param {string} [SOURCE_FILES] - list of source files
+# @param {string} [LIBPATH] - list of library paths (e.g., `-L /foo/bar -L /beep/boop`)
+# @param {string} [LIBRARIES] - list of libraries (e.g., `-lopenblas -lpthread`)
+#
+# @example
+# make
+#
+# @example
+# make all
+#/
+all: $(c_targets)
+
+.PHONY: all
+
+#/
+# Compiles C source files.
+#
+# @private
+# @param {string} CC - C compiler (e.g., `gcc`)
+# @param {string} CFLAGS - C compiler options
+# @param {(string|void)} fPIC - compiler flag determining whether to generate position independent code (e.g., `-fPIC`)
+# @param {string} INCLUDE - list of includes (e.g., `-I /foo/bar`)
+# @param {string} SOURCE_FILES - list of source files
+# @param {string} LIBPATH - list of library paths (e.g., `-L /foo/bar`)
+# @param {string} LIBRARIES - list of libraries (e.g., `-lopenblas`)
+#/
+$(c_targets): %.out: %.c
+	$(QUIET) $(CC) $(CFLAGS) $(fPIC) $(INCLUDE) -o $@ $(SOURCE_FILES) $< $(LIBPATH) -lm $(LIBRARIES)
+
+#/
+# Runs compiled benchmarks.
+#
+# @example
+# make run
+#/
+run: $(c_targets)
+	$(QUIET) ./$<
+
+.PHONY: run
+
+#/
+# Removes generated files.
+#
+# @example
+# make clean
+#/
+clean:
+	$(QUIET) -rm -f *.o *.out
+
+.PHONY: clean