/* stfttr.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int stfttr_(char *transr, char *uplo, integer *n, real *arf,
real *a, integer *lda, integer *info)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2;
/* Local variables */
integer i__, j, k, l, n1, n2, ij, nt, nx2, np1x2;
logical normaltransr;
extern logical lsame_(char *, char *);
logical lower;
extern /* Subroutine */ int xerbla_(char *, integer *);
logical nisodd;
/* -- LAPACK routine (version 3.2) -- */
/* -- Contributed by Fred Gustavson of the IBM Watson Research Center -- */
/* -- November 2008 -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* STFTTR copies a triangular matrix A from rectangular full packed */
/* format (TF) to standard full format (TR). */
/* Arguments */
/* ========= */
/* TRANSR (input) CHARACTER */
/* = 'N': ARF is in Normal format; */
/* = 'T': ARF is in Transpose format. */
/* UPLO (input) CHARACTER */
/* = 'U': A is upper triangular; */
/* = 'L': A is lower triangular. */
/* N (input) INTEGER */
/* The order of the matrices ARF and A. N >= 0. */
/* ARF (input) REAL array, dimension (N*(N+1)/2). */
/* On entry, the upper (if UPLO = 'U') or lower (if UPLO = 'L') */
/* matrix A in RFP format. See the "Notes" below for more */
/* details. */
/* A (output) REAL array, dimension (LDA,N) */
/* On exit, the triangular matrix A. If UPLO = 'U', the */
/* leading N-by-N upper triangular part of the array A contains */
/* the upper triangular matrix, and the strictly lower */
/* triangular part of A is not referenced. If UPLO = 'L', the */
/* leading N-by-N lower triangular part of the array A contains */
/* the lower triangular matrix, and the strictly upper */
/* triangular part of A is not referenced. */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. LDA >= max(1,N). */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* Notes */
/* ===== */
/* We first consider Rectangular Full Packed (RFP) Format when N is */
/* even. We give an example where N = 6. */
/* AP is Upper AP is Lower */
/* 00 01 02 03 04 05 00 */
/* 11 12 13 14 15 10 11 */
/* 22 23 24 25 20 21 22 */
/* 33 34 35 30 31 32 33 */
/* 44 45 40 41 42 43 44 */
/* 55 50 51 52 53 54 55 */
/* Let TRANSR = 'N'. RFP holds AP as follows: */
/* For UPLO = 'U' the upper trapezoid A(0:5,0:2) consists of the last */
/* three columns of AP upper. The lower triangle A(4:6,0:2) consists of */
/* the transpose of the first three columns of AP upper. */
/* For UPLO = 'L' the lower trapezoid A(1:6,0:2) consists of the first */
/* three columns of AP lower. The upper triangle A(0:2,0:2) consists of */
/* the transpose of the last three columns of AP lower. */
/* This covers the case N even and TRANSR = 'N'. */
/* RFP A RFP A */
/* 03 04 05 33 43 53 */
/* 13 14 15 00 44 54 */
/* 23 24 25 10 11 55 */
/* 33 34 35 20 21 22 */
/* 00 44 45 30 31 32 */
/* 01 11 55 40 41 42 */
/* 02 12 22 50 51 52 */
/* Now let TRANSR = 'T'. RFP A in both UPLO cases is just the */
/* transpose of RFP A above. One therefore gets: */
/* RFP A RFP A */
/* 03 13 23 33 00 01 02 33 00 10 20 30 40 50 */
/* 04 14 24 34 44 11 12 43 44 11 21 31 41 51 */
/* 05 15 25 35 45 55 22 53 54 55 22 32 42 52 */
/* We first consider Rectangular Full Packed (RFP) Format when N is */
/* odd. We give an example where N = 5. */
/* AP is Upper AP is Lower */
/* 00 01 02 03 04 00 */
/* 11 12 13 14 10 11 */
/* 22 23 24 20 21 22 */
/* 33 34 30 31 32 33 */
/* 44 40 41 42 43 44 */
/* Let TRANSR = 'N'. RFP holds AP as follows: */
/* For UPLO = 'U' the upper trapezoid A(0:4,0:2) consists of the last */
/* three columns of AP upper. The lower triangle A(3:4,0:1) consists of */
/* the transpose of the first two columns of AP upper. */
/* For UPLO = 'L' the lower trapezoid A(0:4,0:2) consists of the first */
/* three columns of AP lower. The upper triangle A(0:1,1:2) consists of */
/* the transpose of the last two columns of AP lower. */
/* This covers the case N odd and TRANSR = 'N'. */
/* RFP A RFP A */
/* 02 03 04 00 33 43 */
/* 12 13 14 10 11 44 */
/* 22 23 24 20 21 22 */
/* 00 33 34 30 31 32 */
/* 01 11 44 40 41 42 */
/* Now let TRANSR = 'T'. RFP A in both UPLO cases is just the */
/* transpose of RFP A above. One therefore gets: */
/* RFP A RFP A */
/* 02 12 22 00 01 00 10 20 30 40 50 */
/* 03 13 23 33 11 33 11 21 31 41 51 */
/* 04 14 24 34 44 43 44 22 32 42 52 */
/* Reference */
/* ========= */
/* ===================================================================== */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
a_dim1 = *lda - 1 - 0 + 1;
a_offset = 0 + a_dim1 * 0;
a -= a_offset;
/* Function Body */
*info = 0;
normaltransr = lsame_(transr, "N");
lower = lsame_(uplo, "L");
if (! normaltransr && ! lsame_(transr, "T")) {
*info = -1;
} else if (! lower && ! lsame_(uplo, "U")) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*lda < max(1,*n)) {
*info = -6;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("STFTTR", &i__1);
return 0;
}
/* Quick return if possible */
if (*n <= 1) {
if (*n == 1) {
a[0] = arf[0];
}
return 0;
}
/* Size of array ARF(0:nt-1) */
nt = *n * (*n + 1) / 2;
/* set N1 and N2 depending on LOWER: for N even N1=N2=K */
if (lower) {
n2 = *n / 2;
n1 = *n - n2;
} else {
n1 = *n / 2;
n2 = *n - n1;
}
/* If N is odd, set NISODD = .TRUE., LDA=N+1 and A is (N+1)--by--K2. */
/* If N is even, set K = N/2 and NISODD = .FALSE., LDA=N and A is */
/* N--by--(N+1)/2. */
if (*n % 2 == 0) {
k = *n / 2;
nisodd = FALSE_;
if (! lower) {
np1x2 = *n + *n + 2;
}
} else {
nisodd = TRUE_;
if (! lower) {
nx2 = *n + *n;
}
}
if (nisodd) {
/* N is odd */
if (normaltransr) {
/* N is odd and TRANSR = 'N' */
if (lower) {
/* N is odd, TRANSR = 'N', and UPLO = 'L' */
ij = 0;
i__1 = n2;
for (j = 0; j <= i__1; ++j) {
i__2 = n2 + j;
for (i__ = n1; i__ <= i__2; ++i__) {
a[n2 + j + i__ * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (i__ = j; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
}
} else {
/* N is odd, TRANSR = 'N', and UPLO = 'U' */
ij = nt - *n;
i__1 = n1;
for (j = *n - 1; j >= i__1; --j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
i__2 = n1 - 1;
for (l = j - n1; l <= i__2; ++l) {
a[j - n1 + l * a_dim1] = arf[ij];
++ij;
}
ij -= nx2;
}
}
} else {
/* N is odd and TRANSR = 'T' */
if (lower) {
/* N is odd, TRANSR = 'T', and UPLO = 'L' */
ij = 0;
i__1 = n2 - 1;
for (j = 0; j <= i__1; ++j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (i__ = n1 + j; i__ <= i__2; ++i__) {
a[i__ + (n1 + j) * a_dim1] = arf[ij];
++ij;
}
}
i__1 = *n - 1;
for (j = n2; j <= i__1; ++j) {
i__2 = n1 - 1;
for (i__ = 0; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
}
} else {
/* N is odd, TRANSR = 'T', and UPLO = 'U' */
ij = 0;
i__1 = n1;
for (j = 0; j <= i__1; ++j) {
i__2 = *n - 1;
for (i__ = n1; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
}
i__1 = n1 - 1;
for (j = 0; j <= i__1; ++j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (l = n2 + j; l <= i__2; ++l) {
a[n2 + j + l * a_dim1] = arf[ij];
++ij;
}
}
}
}
} else {
/* N is even */
if (normaltransr) {
/* N is even and TRANSR = 'N' */
if (lower) {
/* N is even, TRANSR = 'N', and UPLO = 'L' */
ij = 0;
i__1 = k - 1;
for (j = 0; j <= i__1; ++j) {
i__2 = k + j;
for (i__ = k; i__ <= i__2; ++i__) {
a[k + j + i__ * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (i__ = j; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
}
} else {
/* N is even, TRANSR = 'N', and UPLO = 'U' */
ij = nt - *n - 1;
i__1 = k;
for (j = *n - 1; j >= i__1; --j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
i__2 = k - 1;
for (l = j - k; l <= i__2; ++l) {
a[j - k + l * a_dim1] = arf[ij];
++ij;
}
ij -= np1x2;
}
}
} else {
/* N is even and TRANSR = 'T' */
if (lower) {
/* N is even, TRANSR = 'T', and UPLO = 'L' */
ij = 0;
j = k;
i__1 = *n - 1;
for (i__ = k; i__ <= i__1; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
i__1 = k - 2;
for (j = 0; j <= i__1; ++j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (i__ = k + 1 + j; i__ <= i__2; ++i__) {
a[i__ + (k + 1 + j) * a_dim1] = arf[ij];
++ij;
}
}
i__1 = *n - 1;
for (j = k - 1; j <= i__1; ++j) {
i__2 = k - 1;
for (i__ = 0; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
}
} else {
/* N is even, TRANSR = 'T', and UPLO = 'U' */
ij = 0;
i__1 = k;
for (j = 0; j <= i__1; ++j) {
i__2 = *n - 1;
for (i__ = k; i__ <= i__2; ++i__) {
a[j + i__ * a_dim1] = arf[ij];
++ij;
}
}
i__1 = k - 2;
for (j = 0; j <= i__1; ++j) {
i__2 = j;
for (i__ = 0; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
i__2 = *n - 1;
for (l = k + 1 + j; l <= i__2; ++l) {
a[k + 1 + j + l * a_dim1] = arf[ij];
++ij;
}
}
/* Note that here, on exit of the loop, J = K-1 */
i__1 = j;
for (i__ = 0; i__ <= i__1; ++i__) {
a[i__ + j * a_dim1] = arf[ij];
++ij;
}
}
}
}
return 0;
/* End of STFTTR */
} /* stfttr_ */