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| 2 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
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| 3 | * |
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| 4 | * $Date: 19. March 2015 |
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| 5 | * $Revision: V.1.4.5 |
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| 6 | * |
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| 7 | * Project: CMSIS DSP Library |
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| 8 | * Title: arm_mat_inverse_f64.c |
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| 9 | * |
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| 10 | * Description: Floating-point matrix inverse. |
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| 11 | * |
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| 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
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| 13 | * |
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| 14 | * Redistribution and use in source and binary forms, with or without |
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| 15 | * modification, are permitted provided that the following conditions |
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| 16 | * are met: |
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| 17 | * - Redistributions of source code must retain the above copyright |
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| 18 | * notice, this list of conditions and the following disclaimer. |
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| 19 | * - Redistributions in binary form must reproduce the above copyright |
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| 20 | * notice, this list of conditions and the following disclaimer in |
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| 21 | * the documentation and/or other materials provided with the |
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| 22 | * distribution. |
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| 23 | * - Neither the name of ARM LIMITED nor the names of its contributors |
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| 24 | * may be used to endorse or promote products derived from this |
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| 25 | * software without specific prior written permission. |
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| 26 | * |
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| 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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| 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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| 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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| 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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| 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
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| 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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| 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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| 38 | * POSSIBILITY OF SUCH DAMAGE. |
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| 39 | * -------------------------------------------------------------------- */ |
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| 40 | |||
| 41 | #include "arm_math.h" |
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| 42 | |||
| 43 | /** |
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| 44 | * @ingroup groupMatrix |
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| 45 | */ |
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| 46 | |||
| 47 | /** |
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| 48 | * @defgroup MatrixInv Matrix Inverse |
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| 49 | * |
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| 50 | * Computes the inverse of a matrix. |
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| 51 | * |
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| 52 | * The inverse is defined only if the input matrix is square and non-singular (the determinant |
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| 53 | * is non-zero). The function checks that the input and output matrices are square and of the |
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| 54 | * same size. |
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| 55 | * |
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| 56 | * Matrix inversion is numerically sensitive and the CMSIS DSP library only supports matrix |
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| 57 | * inversion of floating-point matrices. |
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| 58 | * |
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| 59 | * \par Algorithm |
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| 60 | * The Gauss-Jordan method is used to find the inverse. |
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| 61 | * The algorithm performs a sequence of elementary row-operations until it |
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| 62 | * reduces the input matrix to an identity matrix. Applying the same sequence |
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| 63 | * of elementary row-operations to an identity matrix yields the inverse matrix. |
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| 64 | * If the input matrix is singular, then the algorithm terminates and returns error status |
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| 65 | * <code>ARM_MATH_SINGULAR</code>. |
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| 66 | * \image html MatrixInverse.gif "Matrix Inverse of a 3 x 3 matrix using Gauss-Jordan Method" |
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| 67 | */ |
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| 68 | |||
| 69 | /** |
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| 70 | * @addtogroup MatrixInv |
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| 71 | * @{ |
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| 72 | */ |
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| 73 | |||
| 74 | /** |
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| 75 | * @brief Floating-point matrix inverse. |
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| 76 | * @param[in] *pSrc points to input matrix structure |
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| 77 | * @param[out] *pDst points to output matrix structure |
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| 78 | * @return The function returns |
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| 79 | * <code>ARM_MATH_SIZE_MISMATCH</code> if the input matrix is not square or if the size |
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| 80 | * of the output matrix does not match the size of the input matrix. |
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| 81 | * If the input matrix is found to be singular (non-invertible), then the function returns |
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| 82 | * <code>ARM_MATH_SINGULAR</code>. Otherwise, the function returns <code>ARM_MATH_SUCCESS</code>. |
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| 83 | */ |
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| 84 | |||
| 85 | arm_status arm_mat_inverse_f64( |
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| 86 | const arm_matrix_instance_f64 * pSrc, |
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| 87 | arm_matrix_instance_f64 * pDst) |
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| 88 | { |
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| 89 | float64_t *pIn = pSrc->pData; /* input data matrix pointer */ |
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| 90 | float64_t *pOut = pDst->pData; /* output data matrix pointer */ |
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| 91 | float64_t *pInT1, *pInT2; /* Temporary input data matrix pointer */ |
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| 92 | float64_t *pOutT1, *pOutT2; /* Temporary output data matrix pointer */ |
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| 93 | float64_t *pPivotRowIn, *pPRT_in, *pPivotRowDst, *pPRT_pDst; /* Temporary input and output data matrix pointer */ |
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| 94 | uint32_t numRows = pSrc->numRows; /* Number of rows in the matrix */ |
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| 95 | uint32_t numCols = pSrc->numCols; /* Number of Cols in the matrix */ |
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| 96 | |||
| 97 | #ifndef ARM_MATH_CM0_FAMILY |
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| 98 | float64_t maxC; /* maximum value in the column */ |
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| 99 | |||
| 100 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
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| 101 | |||
| 102 | float64_t Xchg, in = 0.0f, in1; /* Temporary input values */ |
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| 103 | uint32_t i, rowCnt, flag = 0u, j, loopCnt, k, l; /* loop counters */ |
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| 104 | arm_status status; /* status of matrix inverse */ |
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| 105 | |||
| 106 | #ifdef ARM_MATH_MATRIX_CHECK |
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| 107 | |||
| 108 | |||
| 109 | /* Check for matrix mismatch condition */ |
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| 110 | if((pSrc->numRows != pSrc->numCols) || (pDst->numRows != pDst->numCols) |
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| 111 | || (pSrc->numRows != pDst->numRows)) |
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| 112 | { |
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| 113 | /* Set status as ARM_MATH_SIZE_MISMATCH */ |
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| 114 | status = ARM_MATH_SIZE_MISMATCH; |
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| 115 | } |
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| 116 | else |
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| 117 | #endif /* #ifdef ARM_MATH_MATRIX_CHECK */ |
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| 118 | |||
| 119 | { |
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| 120 | |||
| 121 | /*-------------------------------------------------------------------------------------------------------------- |
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| 122 | * Matrix Inverse can be solved using elementary row operations. |
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| 123 | * |
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| 124 | * Gauss-Jordan Method: |
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| 125 | * |
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| 126 | * 1. First combine the identity matrix and the input matrix separated by a bar to form an |
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| 127 | * augmented matrix as follows: |
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| 128 | * _ _ _ _ |
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| 129 | * | a11 a12 | 1 0 | | X11 X12 | |
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| 130 | * | | | = | | |
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| 131 | * |_ a21 a22 | 0 1 _| |_ X21 X21 _| |
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| 132 | * |
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| 133 | * 2. In our implementation, pDst Matrix is used as identity matrix. |
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| 134 | * |
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| 135 | * 3. Begin with the first row. Let i = 1. |
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| 136 | * |
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| 137 | * 4. Check to see if the pivot for column i is the greatest of the column. |
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| 138 | * The pivot is the element of the main diagonal that is on the current row. |
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| 139 | * For instance, if working with row i, then the pivot element is aii. |
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| 140 | * If the pivot is not the most significant of the columns, exchange that row with a row |
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| 141 | * below it that does contain the most significant value in column i. If the most |
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| 142 | * significant value of the column is zero, then an inverse to that matrix does not exist. |
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| 143 | * The most significant value of the column is the absolute maximum. |
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| 144 | * |
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| 145 | * 5. Divide every element of row i by the pivot. |
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| 146 | * |
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| 147 | * 6. For every row below and row i, replace that row with the sum of that row and |
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| 148 | * a multiple of row i so that each new element in column i below row i is zero. |
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| 149 | * |
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| 150 | * 7. Move to the next row and column and repeat steps 2 through 5 until you have zeros |
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| 151 | * for every element below and above the main diagonal. |
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| 152 | * |
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| 153 | * 8. Now an identical matrix is formed to the left of the bar(input matrix, pSrc). |
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| 154 | * Therefore, the matrix to the right of the bar is our solution(pDst matrix, pDst). |
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| 155 | *----------------------------------------------------------------------------------------------------------------*/ |
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| 156 | |||
| 157 | /* Working pointer for destination matrix */ |
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| 158 | pOutT1 = pOut; |
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| 159 | |||
| 160 | /* Loop over the number of rows */ |
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| 161 | rowCnt = numRows; |
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| 162 | |||
| 163 | /* Making the destination matrix as identity matrix */ |
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| 164 | while(rowCnt > 0u) |
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| 165 | { |
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| 166 | /* Writing all zeroes in lower triangle of the destination matrix */ |
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| 167 | j = numRows - rowCnt; |
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| 168 | while(j > 0u) |
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| 169 | { |
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| 170 | *pOutT1++ = 0.0f; |
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| 171 | j--; |
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| 172 | } |
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| 173 | |||
| 174 | /* Writing all ones in the diagonal of the destination matrix */ |
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| 175 | *pOutT1++ = 1.0f; |
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| 176 | |||
| 177 | /* Writing all zeroes in upper triangle of the destination matrix */ |
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| 178 | j = rowCnt - 1u; |
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| 179 | while(j > 0u) |
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| 180 | { |
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| 181 | *pOutT1++ = 0.0f; |
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| 182 | j--; |
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| 183 | } |
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| 184 | |||
| 185 | /* Decrement the loop counter */ |
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| 186 | rowCnt--; |
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| 187 | } |
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| 188 | |||
| 189 | /* Loop over the number of columns of the input matrix. |
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| 190 | All the elements in each column are processed by the row operations */ |
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| 191 | loopCnt = numCols; |
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| 192 | |||
| 193 | /* Index modifier to navigate through the columns */ |
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| 194 | l = 0u; |
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| 195 | |||
| 196 | while(loopCnt > 0u) |
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| 197 | { |
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| 198 | /* Check if the pivot element is zero.. |
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| 199 | * If it is zero then interchange the row with non zero row below. |
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| 200 | * If there is no non zero element to replace in the rows below, |
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| 201 | * then the matrix is Singular. */ |
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| 202 | |||
| 203 | /* Working pointer for the input matrix that points |
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| 204 | * to the pivot element of the particular row */ |
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| 205 | pInT1 = pIn + (l * numCols); |
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| 206 | |||
| 207 | /* Working pointer for the destination matrix that points |
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| 208 | * to the pivot element of the particular row */ |
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| 209 | pOutT1 = pOut + (l * numCols); |
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| 210 | |||
| 211 | /* Temporary variable to hold the pivot value */ |
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| 212 | in = *pInT1; |
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| 213 | |||
| 214 | /* Grab the most significant value from column l */ |
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| 215 | maxC = 0; |
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| 216 | for (i = l; i < numRows; i++) |
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| 217 | { |
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| 218 | maxC = *pInT1 > 0 ? (*pInT1 > maxC ? *pInT1 : maxC) : (-*pInT1 > maxC ? -*pInT1 : maxC); |
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| 219 | pInT1 += numCols; |
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| 220 | } |
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| 221 | |||
| 222 | /* Update the status if the matrix is singular */ |
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| 223 | if(maxC == 0.0f) |
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| 224 | { |
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| 225 | return ARM_MATH_SINGULAR; |
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| 226 | } |
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| 227 | |||
| 228 | /* Restore pInT1 */ |
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| 229 | pInT1 = pIn; |
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| 230 | |||
| 231 | /* Destination pointer modifier */ |
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| 232 | k = 1u; |
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| 233 | |||
| 234 | /* Check if the pivot element is the most significant of the column */ |
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| 235 | if( (in > 0.0f ? in : -in) != maxC) |
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| 236 | { |
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| 237 | /* Loop over the number rows present below */ |
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| 238 | i = numRows - (l + 1u); |
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| 239 | |||
| 240 | while(i > 0u) |
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| 241 | { |
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| 242 | /* Update the input and destination pointers */ |
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| 243 | pInT2 = pInT1 + (numCols * l); |
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| 244 | pOutT2 = pOutT1 + (numCols * k); |
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| 245 | |||
| 246 | /* Look for the most significant element to |
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| 247 | * replace in the rows below */ |
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| 248 | if((*pInT2 > 0.0f ? *pInT2: -*pInT2) == maxC) |
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| 249 | { |
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| 250 | /* Loop over number of columns |
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| 251 | * to the right of the pilot element */ |
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| 252 | j = numCols - l; |
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| 253 | |||
| 254 | while(j > 0u) |
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| 255 | { |
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| 256 | /* Exchange the row elements of the input matrix */ |
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| 257 | Xchg = *pInT2; |
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| 258 | *pInT2++ = *pInT1; |
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| 259 | *pInT1++ = Xchg; |
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| 260 | |||
| 261 | /* Decrement the loop counter */ |
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| 262 | j--; |
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| 263 | } |
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| 264 | |||
| 265 | /* Loop over number of columns of the destination matrix */ |
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| 266 | j = numCols; |
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| 267 | |||
| 268 | while(j > 0u) |
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| 269 | { |
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| 270 | /* Exchange the row elements of the destination matrix */ |
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| 271 | Xchg = *pOutT2; |
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| 272 | *pOutT2++ = *pOutT1; |
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| 273 | *pOutT1++ = Xchg; |
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| 274 | |||
| 275 | /* Decrement the loop counter */ |
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| 276 | j--; |
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| 277 | } |
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| 278 | |||
| 279 | /* Flag to indicate whether exchange is done or not */ |
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| 280 | flag = 1u; |
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| 281 | |||
| 282 | /* Break after exchange is done */ |
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| 283 | break; |
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| 284 | } |
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| 285 | |||
| 286 | /* Update the destination pointer modifier */ |
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| 287 | k++; |
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| 288 | |||
| 289 | /* Decrement the loop counter */ |
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| 290 | i--; |
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| 291 | } |
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| 292 | } |
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| 293 | |||
| 294 | /* Update the status if the matrix is singular */ |
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| 295 | if((flag != 1u) && (in == 0.0f)) |
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| 296 | { |
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| 297 | return ARM_MATH_SINGULAR; |
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| 298 | } |
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| 299 | |||
| 300 | /* Points to the pivot row of input and destination matrices */ |
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| 301 | pPivotRowIn = pIn + (l * numCols); |
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| 302 | pPivotRowDst = pOut + (l * numCols); |
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| 303 | |||
| 304 | /* Temporary pointers to the pivot row pointers */ |
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| 305 | pInT1 = pPivotRowIn; |
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| 306 | pInT2 = pPivotRowDst; |
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| 307 | |||
| 308 | /* Pivot element of the row */ |
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| 309 | in = *pPivotRowIn; |
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| 310 | |||
| 311 | /* Loop over number of columns |
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| 312 | * to the right of the pilot element */ |
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| 313 | j = (numCols - l); |
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| 314 | |||
| 315 | while(j > 0u) |
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| 316 | { |
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| 317 | /* Divide each element of the row of the input matrix |
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| 318 | * by the pivot element */ |
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| 319 | in1 = *pInT1; |
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| 320 | *pInT1++ = in1 / in; |
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| 321 | |||
| 322 | /* Decrement the loop counter */ |
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| 323 | j--; |
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| 324 | } |
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| 325 | |||
| 326 | /* Loop over number of columns of the destination matrix */ |
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| 327 | j = numCols; |
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| 328 | |||
| 329 | while(j > 0u) |
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| 330 | { |
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| 331 | /* Divide each element of the row of the destination matrix |
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| 332 | * by the pivot element */ |
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| 333 | in1 = *pInT2; |
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| 334 | *pInT2++ = in1 / in; |
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| 335 | |||
| 336 | /* Decrement the loop counter */ |
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| 337 | j--; |
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| 338 | } |
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| 339 | |||
| 340 | /* Replace the rows with the sum of that row and a multiple of row i |
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| 341 | * so that each new element in column i above row i is zero.*/ |
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| 342 | |||
| 343 | /* Temporary pointers for input and destination matrices */ |
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| 344 | pInT1 = pIn; |
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| 345 | pInT2 = pOut; |
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| 346 | |||
| 347 | /* index used to check for pivot element */ |
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| 348 | i = 0u; |
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| 349 | |||
| 350 | /* Loop over number of rows */ |
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| 351 | /* to be replaced by the sum of that row and a multiple of row i */ |
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| 352 | k = numRows; |
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| 353 | |||
| 354 | while(k > 0u) |
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| 355 | { |
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| 356 | /* Check for the pivot element */ |
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| 357 | if(i == l) |
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| 358 | { |
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| 359 | /* If the processing element is the pivot element, |
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| 360 | only the columns to the right are to be processed */ |
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| 361 | pInT1 += numCols - l; |
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| 362 | |||
| 363 | pInT2 += numCols; |
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| 364 | } |
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| 365 | else |
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| 366 | { |
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| 367 | /* Element of the reference row */ |
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| 368 | in = *pInT1; |
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| 369 | |||
| 370 | /* Working pointers for input and destination pivot rows */ |
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| 371 | pPRT_in = pPivotRowIn; |
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| 372 | pPRT_pDst = pPivotRowDst; |
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| 373 | |||
| 374 | /* Loop over the number of columns to the right of the pivot element, |
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| 375 | to replace the elements in the input matrix */ |
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| 376 | j = (numCols - l); |
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| 377 | |||
| 378 | while(j > 0u) |
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| 379 | { |
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| 380 | /* Replace the element by the sum of that row |
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| 381 | and a multiple of the reference row */ |
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| 382 | in1 = *pInT1; |
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| 383 | *pInT1++ = in1 - (in * *pPRT_in++); |
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| 384 | |||
| 385 | /* Decrement the loop counter */ |
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| 386 | j--; |
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| 387 | } |
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| 388 | |||
| 389 | /* Loop over the number of columns to |
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| 390 | replace the elements in the destination matrix */ |
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| 391 | j = numCols; |
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| 392 | |||
| 393 | while(j > 0u) |
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| 394 | { |
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| 395 | /* Replace the element by the sum of that row |
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| 396 | and a multiple of the reference row */ |
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| 397 | in1 = *pInT2; |
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| 398 | *pInT2++ = in1 - (in * *pPRT_pDst++); |
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| 399 | |||
| 400 | /* Decrement the loop counter */ |
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| 401 | j--; |
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| 402 | } |
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| 403 | |||
| 404 | } |
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| 405 | |||
| 406 | /* Increment the temporary input pointer */ |
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| 407 | pInT1 = pInT1 + l; |
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| 408 | |||
| 409 | /* Decrement the loop counter */ |
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| 410 | k--; |
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| 411 | |||
| 412 | /* Increment the pivot index */ |
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| 413 | i++; |
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| 414 | } |
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| 415 | |||
| 416 | /* Increment the input pointer */ |
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| 417 | pIn++; |
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| 418 | |||
| 419 | /* Decrement the loop counter */ |
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| 420 | loopCnt--; |
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| 421 | |||
| 422 | /* Increment the index modifier */ |
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| 423 | l++; |
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| 424 | } |
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| 425 | |||
| 426 | |||
| 427 | #else |
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| 428 | |||
| 429 | /* Run the below code for Cortex-M0 */ |
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| 430 | |||
| 431 | float64_t Xchg, in = 0.0f; /* Temporary input values */ |
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| 432 | uint32_t i, rowCnt, flag = 0u, j, loopCnt, k, l; /* loop counters */ |
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| 433 | arm_status status; /* status of matrix inverse */ |
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| 434 | |||
| 435 | #ifdef ARM_MATH_MATRIX_CHECK |
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| 436 | |||
| 437 | /* Check for matrix mismatch condition */ |
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| 438 | if((pSrc->numRows != pSrc->numCols) || (pDst->numRows != pDst->numCols) |
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| 439 | || (pSrc->numRows != pDst->numRows)) |
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| 440 | { |
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| 441 | /* Set status as ARM_MATH_SIZE_MISMATCH */ |
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| 442 | status = ARM_MATH_SIZE_MISMATCH; |
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| 443 | } |
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| 444 | else |
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| 445 | #endif /* #ifdef ARM_MATH_MATRIX_CHECK */ |
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| 446 | { |
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| 447 | |||
| 448 | /*-------------------------------------------------------------------------------------------------------------- |
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| 449 | * Matrix Inverse can be solved using elementary row operations. |
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| 450 | * |
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| 451 | * Gauss-Jordan Method: |
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| 452 | * |
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| 453 | * 1. First combine the identity matrix and the input matrix separated by a bar to form an |
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| 454 | * augmented matrix as follows: |
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| 455 | * _ _ _ _ _ _ _ _ |
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| 456 | * | | a11 a12 | | | 1 0 | | | X11 X12 | |
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| 457 | * | | | | | | | = | | |
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| 458 | * |_ |_ a21 a22 _| | |_0 1 _| _| |_ X21 X21 _| |
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| 459 | * |
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| 460 | * 2. In our implementation, pDst Matrix is used as identity matrix. |
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| 461 | * |
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| 462 | * 3. Begin with the first row. Let i = 1. |
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| 463 | * |
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| 464 | * 4. Check to see if the pivot for row i is zero. |
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| 465 | * The pivot is the element of the main diagonal that is on the current row. |
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| 466 | * For instance, if working with row i, then the pivot element is aii. |
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| 467 | * If the pivot is zero, exchange that row with a row below it that does not |
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| 468 | * contain a zero in column i. If this is not possible, then an inverse |
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| 469 | * to that matrix does not exist. |
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| 470 | * |
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| 471 | * 5. Divide every element of row i by the pivot. |
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| 472 | * |
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| 473 | * 6. For every row below and row i, replace that row with the sum of that row and |
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| 474 | * a multiple of row i so that each new element in column i below row i is zero. |
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| 475 | * |
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| 476 | * 7. Move to the next row and column and repeat steps 2 through 5 until you have zeros |
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| 477 | * for every element below and above the main diagonal. |
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| 478 | * |
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| 479 | * 8. Now an identical matrix is formed to the left of the bar(input matrix, src). |
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| 480 | * Therefore, the matrix to the right of the bar is our solution(dst matrix, dst). |
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| 481 | *----------------------------------------------------------------------------------------------------------------*/ |
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| 482 | |||
| 483 | /* Working pointer for destination matrix */ |
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| 484 | pOutT1 = pOut; |
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| 485 | |||
| 486 | /* Loop over the number of rows */ |
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| 487 | rowCnt = numRows; |
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| 488 | |||
| 489 | /* Making the destination matrix as identity matrix */ |
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| 490 | while(rowCnt > 0u) |
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| 491 | { |
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| 492 | /* Writing all zeroes in lower triangle of the destination matrix */ |
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| 493 | j = numRows - rowCnt; |
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| 494 | while(j > 0u) |
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| 495 | { |
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| 496 | *pOutT1++ = 0.0f; |
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| 497 | j--; |
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| 498 | } |
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| 499 | |||
| 500 | /* Writing all ones in the diagonal of the destination matrix */ |
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| 501 | *pOutT1++ = 1.0f; |
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| 502 | |||
| 503 | /* Writing all zeroes in upper triangle of the destination matrix */ |
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| 504 | j = rowCnt - 1u; |
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| 505 | while(j > 0u) |
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| 506 | { |
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| 507 | *pOutT1++ = 0.0f; |
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| 508 | j--; |
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| 509 | } |
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| 510 | |||
| 511 | /* Decrement the loop counter */ |
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| 512 | rowCnt--; |
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| 513 | } |
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| 514 | |||
| 515 | /* Loop over the number of columns of the input matrix. |
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| 516 | All the elements in each column are processed by the row operations */ |
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| 517 | loopCnt = numCols; |
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| 518 | |||
| 519 | /* Index modifier to navigate through the columns */ |
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| 520 | l = 0u; |
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| 521 | //for(loopCnt = 0u; loopCnt < numCols; loopCnt++) |
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| 522 | while(loopCnt > 0u) |
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| 523 | { |
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| 524 | /* Check if the pivot element is zero.. |
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| 525 | * If it is zero then interchange the row with non zero row below. |
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| 526 | * If there is no non zero element to replace in the rows below, |
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| 527 | * then the matrix is Singular. */ |
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| 528 | |||
| 529 | /* Working pointer for the input matrix that points |
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| 530 | * to the pivot element of the particular row */ |
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| 531 | pInT1 = pIn + (l * numCols); |
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| 532 | |||
| 533 | /* Working pointer for the destination matrix that points |
||
| 534 | * to the pivot element of the particular row */ |
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| 535 | pOutT1 = pOut + (l * numCols); |
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| 536 | |||
| 537 | /* Temporary variable to hold the pivot value */ |
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| 538 | in = *pInT1; |
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| 539 | |||
| 540 | /* Destination pointer modifier */ |
||
| 541 | k = 1u; |
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| 542 | |||
| 543 | /* Check if the pivot element is zero */ |
||
| 544 | if(*pInT1 == 0.0f) |
||
| 545 | { |
||
| 546 | /* Loop over the number rows present below */ |
||
| 547 | for (i = (l + 1u); i < numRows; i++) |
||
| 548 | { |
||
| 549 | /* Update the input and destination pointers */ |
||
| 550 | pInT2 = pInT1 + (numCols * l); |
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| 551 | pOutT2 = pOutT1 + (numCols * k); |
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| 552 | |||
| 553 | /* Check if there is a non zero pivot element to |
||
| 554 | * replace in the rows below */ |
||
| 555 | if(*pInT2 != 0.0f) |
||
| 556 | { |
||
| 557 | /* Loop over number of columns |
||
| 558 | * to the right of the pilot element */ |
||
| 559 | for (j = 0u; j < (numCols - l); j++) |
||
| 560 | { |
||
| 561 | /* Exchange the row elements of the input matrix */ |
||
| 562 | Xchg = *pInT2; |
||
| 563 | *pInT2++ = *pInT1; |
||
| 564 | *pInT1++ = Xchg; |
||
| 565 | } |
||
| 566 | |||
| 567 | for (j = 0u; j < numCols; j++) |
||
| 568 | { |
||
| 569 | Xchg = *pOutT2; |
||
| 570 | *pOutT2++ = *pOutT1; |
||
| 571 | *pOutT1++ = Xchg; |
||
| 572 | } |
||
| 573 | |||
| 574 | /* Flag to indicate whether exchange is done or not */ |
||
| 575 | flag = 1u; |
||
| 576 | |||
| 577 | /* Break after exchange is done */ |
||
| 578 | break; |
||
| 579 | } |
||
| 580 | |||
| 581 | /* Update the destination pointer modifier */ |
||
| 582 | k++; |
||
| 583 | } |
||
| 584 | } |
||
| 585 | |||
| 586 | /* Update the status if the matrix is singular */ |
||
| 587 | if((flag != 1u) && (in == 0.0f)) |
||
| 588 | { |
||
| 589 | return ARM_MATH_SINGULAR; |
||
| 590 | } |
||
| 591 | |||
| 592 | /* Points to the pivot row of input and destination matrices */ |
||
| 593 | pPivotRowIn = pIn + (l * numCols); |
||
| 594 | pPivotRowDst = pOut + (l * numCols); |
||
| 595 | |||
| 596 | /* Temporary pointers to the pivot row pointers */ |
||
| 597 | pInT1 = pPivotRowIn; |
||
| 598 | pOutT1 = pPivotRowDst; |
||
| 599 | |||
| 600 | /* Pivot element of the row */ |
||
| 601 | in = *(pIn + (l * numCols)); |
||
| 602 | |||
| 603 | /* Loop over number of columns |
||
| 604 | * to the right of the pilot element */ |
||
| 605 | for (j = 0u; j < (numCols - l); j++) |
||
| 606 | { |
||
| 607 | /* Divide each element of the row of the input matrix |
||
| 608 | * by the pivot element */ |
||
| 609 | *pInT1 = *pInT1 / in; |
||
| 610 | pInT1++; |
||
| 611 | } |
||
| 612 | for (j = 0u; j < numCols; j++) |
||
| 613 | { |
||
| 614 | /* Divide each element of the row of the destination matrix |
||
| 615 | * by the pivot element */ |
||
| 616 | *pOutT1 = *pOutT1 / in; |
||
| 617 | pOutT1++; |
||
| 618 | } |
||
| 619 | |||
| 620 | /* Replace the rows with the sum of that row and a multiple of row i |
||
| 621 | * so that each new element in column i above row i is zero.*/ |
||
| 622 | |||
| 623 | /* Temporary pointers for input and destination matrices */ |
||
| 624 | pInT1 = pIn; |
||
| 625 | pOutT1 = pOut; |
||
| 626 | |||
| 627 | for (i = 0u; i < numRows; i++) |
||
| 628 | { |
||
| 629 | /* Check for the pivot element */ |
||
| 630 | if(i == l) |
||
| 631 | { |
||
| 632 | /* If the processing element is the pivot element, |
||
| 633 | only the columns to the right are to be processed */ |
||
| 634 | pInT1 += numCols - l; |
||
| 635 | pOutT1 += numCols; |
||
| 636 | } |
||
| 637 | else |
||
| 638 | { |
||
| 639 | /* Element of the reference row */ |
||
| 640 | in = *pInT1; |
||
| 641 | |||
| 642 | /* Working pointers for input and destination pivot rows */ |
||
| 643 | pPRT_in = pPivotRowIn; |
||
| 644 | pPRT_pDst = pPivotRowDst; |
||
| 645 | |||
| 646 | /* Loop over the number of columns to the right of the pivot element, |
||
| 647 | to replace the elements in the input matrix */ |
||
| 648 | for (j = 0u; j < (numCols - l); j++) |
||
| 649 | { |
||
| 650 | /* Replace the element by the sum of that row |
||
| 651 | and a multiple of the reference row */ |
||
| 652 | *pInT1 = *pInT1 - (in * *pPRT_in++); |
||
| 653 | pInT1++; |
||
| 654 | } |
||
| 655 | /* Loop over the number of columns to |
||
| 656 | replace the elements in the destination matrix */ |
||
| 657 | for (j = 0u; j < numCols; j++) |
||
| 658 | { |
||
| 659 | /* Replace the element by the sum of that row |
||
| 660 | and a multiple of the reference row */ |
||
| 661 | *pOutT1 = *pOutT1 - (in * *pPRT_pDst++); |
||
| 662 | pOutT1++; |
||
| 663 | } |
||
| 664 | |||
| 665 | } |
||
| 666 | /* Increment the temporary input pointer */ |
||
| 667 | pInT1 = pInT1 + l; |
||
| 668 | } |
||
| 669 | /* Increment the input pointer */ |
||
| 670 | pIn++; |
||
| 671 | |||
| 672 | /* Decrement the loop counter */ |
||
| 673 | loopCnt--; |
||
| 674 | /* Increment the index modifier */ |
||
| 675 | l++; |
||
| 676 | } |
||
| 677 | |||
| 678 | |||
| 679 | #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
||
| 680 | |||
| 681 | /* Set status as ARM_MATH_SUCCESS */ |
||
| 682 | status = ARM_MATH_SUCCESS; |
||
| 683 | |||
| 684 | if((flag != 1u) && (in == 0.0f)) |
||
| 685 | { |
||
| 686 | pIn = pSrc->pData; |
||
| 687 | for (i = 0; i < numRows * numCols; i++) |
||
| 688 | { |
||
| 689 | if (pIn[i] != 0.0f) |
||
| 690 | break; |
||
| 691 | } |
||
| 692 | |||
| 693 | if (i == numRows * numCols) |
||
| 694 | status = ARM_MATH_SINGULAR; |
||
| 695 | } |
||
| 696 | } |
||
| 697 | /* Return to application */ |
||
| 698 | return (status); |
||
| 699 | } |
||
| 700 | |||
| 701 | /** |
||
| 702 | * @} end of MatrixInv group |
||
| 703 | */ |