feat: add C ndarray interface and refactor implementation

Author: aayush0325

lib/node_modules/@stdlib/stats/base/dnanmaxabs/include/stdlib/stats/base/dnanmaxabs.h

@@ -19,7 +19,7 @@
 #ifndef STDLIB_STATS_BASE_DNANMAXABS_H
 #define STDLIB_STATS_BASE_DNANMAXABS_H
 
-#include <stdint.h>
+#include "stdlib/blas/base/shared.h"
 
 /*
 * If C++, prevent name mangling so that the compiler emits a binary file having undecorated names, thus mirroring the behavior of a C compiler.
@@ -31,7 +31,12 @@ extern "C" {
 /**
 * Computes the maximum absolute value of a double-precision floating-point strided array, ignoring `NaN` values.
 */
-double stdlib_strided_dnanmaxabs( const int64_t N, const double *X, const int64_t stride );
+double API_SUFFIX(stdlib_strided_dnanmaxabs)( const CBLAS_INT N, const double *X, const CBLAS_INT strideX );
+
+/**
+* Computes the maximum absolute value of a double-precision floating-point strided array, ignoring `NaN` values and using alternative indexing semantics .
+*/
+double API_SUFFIX(stdlib_strided_dnanmaxabs_ndarray)( const CBLAS_INT N, const double *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );
 
 #ifdef __cplusplus
 }

lib/node_modules/@stdlib/stats/base/dnanmaxabs/src/addon.cpp

@@ -0,0 +1,83 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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/dnanmaxabs.h"
+#include "stdlib/math/base/assert/is_nan.h"
+#include "stdlib/blas/base/shared.h"
+#include "stdlib/math/base/special/abs.h"
+#include "stdlib/strided/base/stride2offset.h"
+
+/**
+* Computes the maximum absolute value of a double-precision floating-point strided array, ignoring `NaN` values.
+*
+* @param N        number of indexed elements
+* @param X        input array
+* @param strideX  stride length
+* @return         output value
+*/
+double API_SUFFIX(stdlib_strided_dnanmaxabs)( const CBLAS_INT N, const double *X, const CBLAS_INT strideX ) {
+	const CBLAS_INT ox = stdlib_strided_stride2offset( N, strideX );
+	return API_SUFFIX(stdlib_strided_dnanmaxabs_ndarray)( N, X, strideX, ox );
+}
+
+/**
+* Computes the maximum absolute value of a double-precision floating-point strided array, ignoring `NaN` values and using alternative indexing semantics.
+*
+* @param N        number of indexed elements
+* @param X        input array
+* @param strideX  stride length
+* @param offsetX  starting index for X
+* @return         output value
+*/
+double API_SUFFIX(stdlib_strided_dnanmaxabs_ndarray)( const CBLAS_INT N, const double *X, const CBLAS_INT strideX, const CBLAS_INT offsetX ) {
+	double max;
+	CBLAS_INT ix;
+	CBLAS_INT i;
+	double v;
+
+	if ( N <= 0 ) {
+		return 0.0 / 0.0; // NaN
+	}
+	if ( N == 1 || strideX == 0 ) {
+		return stdlib_base_abs( X[ offsetX ] );
+	}
+	ix = offsetX;
+	for ( i = 0; i < N; i++ ) {
+		v = X[ ix ];
+		if ( v == v ) {
+			break;
+		}
+		ix += strideX;
+	}
+	if ( i == N ) {
+		return 0.0 / 0.0; // NaN
+	}
+	max = stdlib_base_abs( v );
+	i += 1;
+	for (; i < N; i++ ) {
+		ix += strideX;
+		v = stdlib_base_abs( X[ ix ] );
+		if ( stdlib_base_is_nan( v ) ) {
+			continue;
+		}
+		if ( v > max ) {
+			max = v;
+		}
+	}
+	return max;
+}