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ec100cf00f
Improved function documentation Fixed dlarfb and dlarft and added full tests Added dgelq2 Working Dgels Fix many comments and tests Many PR comment responses Responded to more PR comments Many PR comments
32 lines
744 B
Go
32 lines
744 B
Go
// Copyright ©2015 The gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package native
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// Iladlc scans a matrix for its last non-zero column. Returns -1 if the matrix
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// is all zeros.
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func (Implementation) Iladlc(m, n int, a []float64, lda int) int {
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if n == 0 || m == 0 {
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return n - 1
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}
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checkMatrix(m, n, a, lda)
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// Test common case where corner is non-zero.
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if a[n-1] != 0 || a[(m-1)*lda+(n-1)] != 0 {
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return n - 1
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}
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// Scan each row tracking the highest column seen.
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highest := -1
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for i := 0; i < m; i++ {
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for j := n - 1; j >= 0; j-- {
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if a[i*lda+j] != 0 {
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highest = max(highest, j)
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break
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}
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}
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}
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return highest
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}
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