diff options
Diffstat (limited to 'gsl-1.9/cblas/source_tbsv_r.h')
| -rw-r--r-- | gsl-1.9/cblas/source_tbsv_r.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/gsl-1.9/cblas/source_tbsv_r.h b/gsl-1.9/cblas/source_tbsv_r.h new file mode 100644 index 0000000..30227e7 --- /dev/null +++ b/gsl-1.9/cblas/source_tbsv_r.h @@ -0,0 +1,123 @@ +/* blas/source_tbsv_r.h + * + * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +{ + const int nonunit = (Diag == CblasNonUnit); + INDEX i, j; + const int Trans = (TransA != CblasConjTrans) ? TransA : CblasTrans; + + if (N == 0) + return; + + /* form x := inv( A )*x */ + + if ((order == CblasRowMajor && Trans == CblasNoTrans && Uplo == CblasUpper) + || (order == CblasColMajor && Trans == CblasTrans && Uplo == CblasLower)) { + /* backsubstitution */ + INDEX ix = OFFSET(N, incX) + incX * (N - 1); + for (i = N; i > 0 && i--;) { + BASE tmp = X[ix]; + const INDEX j_min = i + 1; + const INDEX j_max = GSL_MIN(N, i + K + 1); + INDEX jx = OFFSET(N, incX) + j_min * incX; + for (j = j_min; j < j_max; j++) { + const BASE Aij = A[lda * i + (j - i)]; + tmp -= Aij * X[jx]; + jx += incX; + } + if (nonunit) { + X[ix] = tmp / A[lda * i + 0]; + } else { + X[ix] = tmp; + } + ix -= incX; + } + } else if ((order == CblasRowMajor && Trans == CblasNoTrans && Uplo == CblasLower) + || (order == CblasColMajor && Trans == CblasTrans && Uplo == CblasUpper)) { + + /* forward substitution */ + INDEX ix = OFFSET(N, incX); + + for (i = 0; i < N; i++) { + BASE tmp = X[ix]; + const INDEX j_min = (i > K ? i - K : 0); + const INDEX j_max = i; + INDEX jx = OFFSET(N, incX) + j_min * incX; + for (j = j_min; j < j_max; j++) { + const BASE Aij = A[lda * i + (K + j - i)]; + tmp -= Aij * X[jx]; + jx += incX; + } + if (nonunit) { + X[ix] = tmp / A[lda * i + K]; + } else { + X[ix] = tmp; + } + ix += incX; + } + } else if ((order == CblasRowMajor && Trans == CblasTrans && Uplo == CblasUpper) + || (order == CblasColMajor && Trans == CblasNoTrans && Uplo == CblasLower)) { + + /* form x := inv( A' )*x */ + + /* forward substitution */ + INDEX ix = OFFSET(N, incX); + for (i = 0; i < N; i++) { + BASE tmp = X[ix]; + const INDEX j_min = (K > i ? 0 : i - K); + const INDEX j_max = i; + INDEX jx = OFFSET(N, incX) + j_min * incX; + for (j = j_min; j < j_max; j++) { + const BASE Aji = A[(i - j) + lda * j]; + tmp -= Aji * X[jx]; + jx += incX; + } + if (nonunit) { + X[ix] = tmp / A[0 + lda * i]; + } else { + X[ix] = tmp; + } + ix += incX; + } + } else if ((order == CblasRowMajor && Trans == CblasTrans && Uplo == CblasLower) + || (order == CblasColMajor && Trans == CblasNoTrans && Uplo == CblasUpper)) { + + /* backsubstitution */ + INDEX ix = OFFSET(N, incX) + (N - 1) * incX; + for (i = N; i > 0 && i--;) { + BASE tmp = X[ix]; + const INDEX j_min = i + 1; + const INDEX j_max = GSL_MIN(N, i + K + 1); + INDEX jx = OFFSET(N, incX) + j_min * incX; + for (j = j_min; j < j_max; j++) { + const BASE Aji = A[(K + i - j) + lda * j]; + tmp -= Aji * X[jx]; + jx += incX; + } + if (nonunit) { + X[ix] = tmp / A[K + lda * i]; + } else { + X[ix] = tmp; + } + ix -= incX; + } + } else { + BLAS_ERROR("unrecognized operation"); + } +} |