feat: complete initial implementation for dgttrf

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Author: aayush0325

lib/node_modules/@stdlib/lapack/base/dgttrf/lib/dgttrf.js

@@ -0,0 +1,66 @@
+/**
+* @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 format = require( '@stdlib/string/format' );
+var base = require( './base.js' );
+
+
+// MAIN //
+
+/**
+* Computes an LU factorization of a real tri diagonal matrix A using elimination with partial pivoting and row interchanges.
+*
+* @param {NonNegativeInteger} N - order of `A`
+* @param {Float64Array} DL - sub diagonal elements of `A`
+* @param {Float64Array} D - diagonal elements of `A`
+* @param {Float64Array} DU - diagonal elements of `A`
+* @param {Float64Array} DU2 - diagonal elements of `A`
+* @param {Int32Array} IPIV - vector of pivot indices
+* @throws {RangeError} first argument must be a nonnegative integer
+* @returns {integer} status code
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+*
+* var DL = new Float64Array( [ 1.0, 1.0 ] );
+* var D = new Float64Array( [ 2.0, 3.0, 1.0 ] );
+* var DU = new Float64Array( [ 1.0, 1.0 ] );
+* var DU2 = new Float64Array( [ 0.0 ] );
+* var IPIV = new Int32Array( [ 0, 1, 2 ] );
+*
+* dgttrf( 3, DL, D, DU, DU2, IPIV );
+* // DL => <Float64Array>[ 0.5, 0.4 ]
+* // D => <Float64Array>[ 2, 2.5, 0.6 ]
+* // DU => <Float64Array>[ 1, 1 ]
+* // DU2 => <Float64Array>[ 0 ]
+*/
+function dgttrf( N, DL, D, DU, DU2, IPIV ) {
+	if ( N < 0 ) {
+		throw new RangeError( format( 'invalid argument. First argument must be a nonnegative integer. Value: `%d`.', N ) );
+	}
+	return base( N, DL, 1, 0, D, 1, 0, DU, 1, 0, DU2, 1, 0, IPIV, 1, 0 );
+}
+
+
+// EXPORTS //
+
+module.exports = dgttrf;

lib/node_modules/@stdlib/lapack/base/dgttrf/lib/index.js

@@ -0,0 +1,80 @@
+/**
+* @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';
+
+/**
+* LAPACK routine to compute an LU factorization of a real tri diagonal matrix A using elimination with partial pivoting and row interchanges.
+*
+* @module @stdlib/lapack/base/dgttrf
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var dgttrf = require( '@stdlib/lapack/base/dgttrf' );
+*
+* var DL = new Float64Array( [ 1.0, 1.0 ] );
+* var D = new Float64Array( [ 2.0, 3.0, 1.0 ] );
+* var DU = new Float64Array( [ 1.0, 1.0 ] );
+* var DU2 = new Float64Array( [ 0.0 ] );
+* var IPIV = new Int32Array( [ 0, 1, 2 ] );
+*
+* dgttrf( 3, DL, D, DU, DU2, IPIV );
+* // DL => <Float64Array>[ 0.5, 0.4 ]
+* // D => <Float64Array>[ 2, 2.5, 0.6 ]
+* // DU => <Float64Array>[ 1, 1 ]
+* // DU2 => <Float64Array>[ 0 ]
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var dgttrf = require( '@stdlib/lapack/base/dgttrf' );
+*
+* var DL = new Float64Array( [ 1.0, 1.0 ] );
+* var D = new Float64Array( [ 2.0, 3.0, 1.0 ] );
+* var DU = new Float64Array( [ 1.0, 1.0 ] );
+* var DU2 = new Float64Array( [ 0.0 ] );
+* var IPIV = new Int32Array( [ 0, 1, 2 ] );
+*
+* dgttrf( 3, DL, 1, 0, D, 1, 0, DU, 1, 0, DU2, 1, 0, IPIV, 1, 0 );
+* // DL => <Float64Array>[ 0.5, 0.4 ]
+* // D => <Float64Array>[ 2, 2.5, 0.6 ]
+* // DU => <Float64Array>[ 1, 1 ]
+* // DU2 => <Float64Array>[ 0 ]
+*/
+
+// MODULES //
+
+var join = require( 'path' ).join;
+var tryRequire = require( '@stdlib/utils/try-require' );
+var isError = require( '@stdlib/assert/is-error' );
+var main = require( './main.js' );
+
+
+// MAIN //
+
+var dgttrf;
+var tmp = tryRequire( join( __dirname, './native.js' ) );
+if ( isError( tmp ) ) {
+	dgttrf = main;
+} else {
+	dgttrf = tmp;
+}
+
+
+// EXPORTS //
+
+module.exports = dgttrf;

lib/node_modules/@stdlib/lapack/base/dgttrf/lib/main.js

@@ -0,0 +1,35 @@
+/**
+* @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 setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
+var dgttrf = require( './dgttrf.js' );
+var ndarray = require( './ndarray.js' );
+
+
+// MAIN //
+
+setReadOnly( dgttrf, 'ndarray', ndarray );
+
+
+// EXPORTS //
+
+module.exports = dgttrf;

lib/node_modules/@stdlib/lapack/base/dgttrf/lib/ndarray.js

@@ -0,0 +1,76 @@
+/**
+* @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 format = require( '@stdlib/string/format' );
+var base = require( './base.js' );
+
+
+// MAIN //
+
+/**
+* Computes an LU factorization of a real tri diagonal matrix A using elimination with partial pivoting and row interchanges.
+*
+* @param {NonNegativeInteger} N - order of `A`
+* @param {Float64Array} DL - sub diagonal elements of `A`
+* @param {integer} strideDL - stride of the sub diagonal elements of `A`
+* @param {NonNegativeInteger} offsetDL - offset of the sub diagonal elements of `A`
+* @param {Float64Array} D - diagonal elements of `A`
+* @param {integer} strideD - stride of the diagonal elements of `A`
+* @param {NonNegativeInteger} offsetD - offset of the diagonal elements of `A`
+* @param {Float64Array} DU - diagonal elements of `A`
+* @param {integer} strideDU - stride of the first super diagonal elements of `A`
+* @param {NonNegativeInteger} offsetDU - offset of the first super diagonal elements of `A`
+* @param {Float64Array} DU2 - diagonal elements of `A`
+* @param {integer} strideDU2 - stride of the second super diagonal elements of `A`
+* @param {NonNegativeInteger} offsetDU2 - offset of the second super diagonal elements of `A`
+* @param {Int32Array} IPIV - vector of pivot indices
+* @param {integer} strideIPIV - `IPIV` stride length
+* @param {NonNegativeInteger} offsetIPIV - index offset for `IPIV`
+* @throws {RangeError} first argument must be a nonnegative integer
+* @returns {integer} status code
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+*
+* var DL = new Float64Array( [ 1.0, 1.0 ] );
+* var D = new Float64Array( [ 2.0, 3.0, 1.0 ] );
+* var DU = new Float64Array( [ 1.0, 1.0 ] );
+* var DU2 = new Float64Array( [ 0.0 ] );
+* var IPIV = new Int32Array( [ 0, 1, 2 ] );
+*
+* dgttrf( 3, DL, 1, 0, D, 1, 0, DU, 1, 0, DU2, 1, 0, IPIV, 1, 0 );
+* // DL => <Float64Array>[ 0.5, 0.4 ]
+* // D => <Float64Array>[ 2, 2.5, 0.6 ]
+* // DU => <Float64Array>[ 1, 1 ]
+* // DU2 => <Float64Array>[ 0 ]
+*/
+function dgttrf( N, DL, strideDL, offsetDL, D, strideD, offsetD, DU, strideDU, offsetDU, DU2, strideDU2, offsetDU2, IPIV, strideIPIV, offsetIPIV ) { // eslint-disable-line max-len, max-params
+	if ( N < 0 ) {
+		throw new RangeError( format( 'invalid argument. First argument must be a nonnegative integer. Value: `%d`.', N ) );
+	}
+	return base( N, DL, strideDL, offsetDL, D, strideD, offsetD, DU, strideDU, offsetDU, DU2, strideDU2, offsetDU2, IPIV, strideIPIV, offsetIPIV ); // eslint-disable-line max-len
+}
+
+
+// EXPORTS //
+
+module.exports = dgttrf;