diff options
author | Eric Andersen <andersen@codepoet.org> | 2001-05-10 00:40:28 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2001-05-10 00:40:28 +0000 |
commit | 1077fa4d772832f77a677ce7fb7c2d513b959e3f (patch) | |
tree | 579bee13fb0b58d2800206366ec2caecbb15f3fc /libm/double/mtransp.c | |
parent | 22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff) |
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/double/mtransp.c')
-rw-r--r-- | libm/double/mtransp.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libm/double/mtransp.c b/libm/double/mtransp.c new file mode 100644 index 000000000..b4a54dd0f --- /dev/null +++ b/libm/double/mtransp.c @@ -0,0 +1,61 @@ +/* mtransp.c + * + * Matrix transpose + * + * + * + * SYNOPSIS: + * + * int n; + * double A[n*n], T[n*n]; + * + * mtransp( n, A, T ); + * + * + * + * DESCRIPTION: + * + * + * T[r][c] = A[c][r] + * + * + * Transposes the n by n square matrix A and puts the result in T. + * The output, T, may occupy the same storage as A. + * + * + * + */ + + +mtransp( n, A, T ) +int n; +double *A, *T; +{ +int i, j, np1; +double *pAc, *pAr, *pTc, *pTr, *pA0, *pT0; +double x, y; + +np1 = n+1; +pA0 = A; +pT0 = T; +for( i=0; i<n-1; i++ ) /* row index */ + { + pAc = pA0; /* next diagonal element of input */ + pAr = pAc + n; /* next row down underneath the diagonal element */ + pTc = pT0; /* next diagonal element of the output */ + pTr = pTc + n; /* next row underneath */ + *pTc++ = *pAc++; /* copy the diagonal element */ + for( j=i+1; j<n; j++ ) /* column index */ + { + x = *pAr; + *pTr = *pAc++; + *pTc++ = x; + pAr += n; + pTr += n; + } + pA0 += np1; /* &A[n*i+i] for next i */ + pT0 += np1; /* &T[n*i+i] for next i */ + } +*pT0 = *pA0; /* copy the diagonal element */ +} + |