blob: d54ff679f19410af578880282da791d63d2eb537 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_mat_solve_lower_triangular_f64.c
* Description: Solve linear system LT X = A with LT lower triangular matrix
*
* $Date: 23 April 2021
* $Revision: V1.9.0
*
* Target Processor: Cortex-M and Cortex-A cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* 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
*
* 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 "dsp/matrix_functions.h"
/**
@ingroup groupMatrix
*/
/**
@addtogroup MatrixInv
@{
*/
/**
* @brief Solve LT . X = A where LT is a lower triangular matrix
* @param[in] lt The lower triangular matrix
* @param[in] a The matrix a
* @param[out] dst The solution X of LT . X = A
* @return The function returns ARM_MATH_SINGULAR, if the system can't be solved.
*/
arm_status arm_mat_solve_lower_triangular_f64(
const arm_matrix_instance_f64 * lt,
const arm_matrix_instance_f64 * a,
arm_matrix_instance_f64 * dst)
{
arm_status status; /* status of matrix inverse */
#ifdef ARM_MATH_MATRIX_CHECK
/* Check for matrix mismatch condition */
if ((lt->numRows != lt->numCols) ||
(lt->numRows != a->numRows) )
{
/* Set status as ARM_MATH_SIZE_MISMATCH */
status = ARM_MATH_SIZE_MISMATCH;
}
else
#endif /* #ifdef ARM_MATH_MATRIX_CHECK */
{
/* a1 b1 c1 x1 = a1
b2 c2 x2 a2
c3 x3 a3
x3 = a3 / c3
x2 = (a2 - c2 x3) / b2
*/
int i,j,k,n,cols;
float64_t *pX = dst->pData;
float64_t *pLT = lt->pData;
float64_t *pA = a->pData;
float64_t *lt_row;
float64_t *a_col;
n = dst->numRows;
cols = dst->numCols;
for(j=0; j < cols; j ++)
{
a_col = &pA[j];
for(i=0; i < n ; i++)
{
float64_t tmp=a_col[i * cols];
lt_row = &pLT[n*i];
for(k=0; k < i; k++)
{
tmp -= lt_row[k] * pX[cols*k+j];
}
if (lt_row[i]==0.0)
{
return(ARM_MATH_SINGULAR);
}
tmp = tmp / lt_row[i];
pX[i*cols+j] = tmp;
}
}
status = ARM_MATH_SUCCESS;
}
/* Return to application */
return (status);
}
/**
@} end of MatrixInv group
*/
|
