/* slasr.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 "clapack.h" /* Subroutine */ int slasr_(char *side, char *pivot, char *direct, integer *m, integer *n, real *c__, real *s, real *a, integer *lda) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; /* Local variables */ integer i__, j, info; real temp; extern logical lsame_(char *, char *); real ctemp, stemp; extern /* Subroutine */ int xerbla_(char *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* SLASR applies a sequence of plane rotations to a real matrix A, */ /* from either the left or the right. */ /* When SIDE = 'L', the transformation takes the form */ /* A := P*A */ /* and when SIDE = 'R', the transformation takes the form */ /* A := A*P**T */ /* where P is an orthogonal matrix consisting of a sequence of z plane */ /* rotations, with z = M when SIDE = 'L' and z = N when SIDE = 'R', */ /* and P**T is the transpose of P. */ /* When DIRECT = 'F' (Forward sequence), then */ /* P = P(z-1) * ... * P(2) * P(1) */ /* and when DIRECT = 'B' (Backward sequence), then */ /* P = P(1) * P(2) * ... * P(z-1) */ /* where P(k) is a plane rotation matrix defined by the 2-by-2 rotation */ /* R(k) = ( c(k) s(k) ) */ /* = ( -s(k) c(k) ). */ /* When PIVOT = 'V' (Variable pivot), the rotation is performed */ /* for the plane (k,k+1), i.e., P(k) has the form */ /* P(k) = ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* ( c(k) s(k) ) */ /* ( -s(k) c(k) ) */ /* ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* where R(k) appears as a rank-2 modification to the identity matrix in */ /* rows and columns k and k+1. */ /* When PIVOT = 'T' (Top pivot), the rotation is performed for the */ /* plane (1,k+1), so P(k) has the form */ /* P(k) = ( c(k) s(k) ) */ /* ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* ( -s(k) c(k) ) */ /* ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* where R(k) appears in rows and columns 1 and k+1. */ /* Similarly, when PIVOT = 'B' (Bottom pivot), the rotation is */ /* performed for the plane (k,z), giving P(k) the form */ /* P(k) = ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* ( c(k) s(k) ) */ /* ( 1 ) */ /* ( ... ) */ /* ( 1 ) */ /* ( -s(k) c(k) ) */ /* where R(k) appears in rows and columns k and z. The rotations are */ /* performed without ever forming P(k) explicitly. */ /* Arguments */ /* ========= */ /* SIDE (input) CHARACTER*1 */ /* Specifies whether the plane rotation matrix P is applied to */ /* A on the left or the right. */ /* = 'L': Left, compute A := P*A */ /* = 'R': Right, compute A:= A*P**T */ /* PIVOT (input) CHARACTER*1 */ /* Specifies the plane for which P(k) is a plane rotation */ /* matrix. */ /* = 'V': Variable pivot, the plane (k,k+1) */ /* = 'T': Top pivot, the plane (1,k+1) */ /* = 'B': Bottom pivot, the plane (k,z) */ /* DIRECT (input) CHARACTER*1 */ /* Specifies whether P is a forward or backward sequence of */ /* plane rotations. */ /* = 'F': Forward, P = P(z-1)*...*P(2)*P(1) */ /* = 'B': Backward, P = P(1)*P(2)*...*P(z-1) */ /* M (input) INTEGER */ /* The number of rows of the matrix A. If m <= 1, an immediate */ /* return is effected. */ /* N (input) INTEGER */ /* The number of columns of the matrix A. If n <= 1, an */ /* immediate return is effected. */ /* C (input) REAL array, dimension */ /* (M-1) if SIDE = 'L' */ /* (N-1) if SIDE = 'R' */ /* The cosines c(k) of the plane rotations. */ /* S (input) REAL array, dimension */ /* (M-1) if SIDE = 'L' */ /* (N-1) if SIDE = 'R' */ /* The sines s(k) of the plane rotations. The 2-by-2 plane */ /* rotation part of the matrix P(k), R(k), has the form */ /* R(k) = ( c(k) s(k) ) */ /* ( -s(k) c(k) ). */ /* A (input/output) REAL array, dimension (LDA,N) */ /* The M-by-N matrix A. On exit, A is overwritten by P*A if */ /* SIDE = 'R' or by A*P**T if SIDE = 'L'. */ /* LDA (input) INTEGER */ /* The leading dimension of the array A. LDA >= max(1,M). */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Test the input parameters */ /* Parameter adjustments */ --c__; --s; a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ info = 0; if (! (lsame_(side, "L") || lsame_(side, "R"))) { info = 1; } else if (! (lsame_(pivot, "V") || lsame_(pivot, "T") || lsame_(pivot, "B"))) { info = 2; } else if (! (lsame_(direct, "F") || lsame_(direct, "B"))) { info = 3; } else if (*m < 0) { info = 4; } else if (*n < 0) { info = 5; } else if (*lda < max(1,*m)) { info = 9; } if (info != 0) { xerbla_("SLASR ", &info); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } if (lsame_(side, "L")) { /* Form P * A */ if (lsame_(pivot, "V")) { if (lsame_(direct, "F")) { i__1 = *m - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[j + 1 + i__ * a_dim1]; a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j + i__ * a_dim1]; /* L10: */ } } /* L20: */ } } else if (lsame_(direct, "B")) { for (j = *m - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[j + 1 + i__ * a_dim1]; a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j + i__ * a_dim1]; /* L30: */ } } /* L40: */ } } } else if (lsame_(pivot, "T")) { if (lsame_(direct, "F")) { i__1 = *m; for (j = 2; j <= i__1; ++j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = ctemp * temp - stemp * a[ i__ * a_dim1 + 1]; a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[ i__ * a_dim1 + 1]; /* L50: */ } } /* L60: */ } } else if (lsame_(direct, "B")) { for (j = *m; j >= 2; --j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = ctemp * temp - stemp * a[ i__ * a_dim1 + 1]; a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[ i__ * a_dim1 + 1]; /* L70: */ } } /* L80: */ } } } else if (lsame_(pivot, "B")) { if (lsame_(direct, "F")) { i__1 = *m - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1] + ctemp * temp; a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * a_dim1] - stemp * temp; /* L90: */ } } /* L100: */ } } else if (lsame_(direct, "B")) { for (j = *m - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[j + i__ * a_dim1]; a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1] + ctemp * temp; a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * a_dim1] - stemp * temp; /* L110: */ } } /* L120: */ } } } } else if (lsame_(side, "R")) { /* Form A * P' */ if (lsame_(pivot, "V")) { if (lsame_(direct, "F")) { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[i__ + (j + 1) * a_dim1]; a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp * a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = stemp * temp + ctemp * a[ i__ + j * a_dim1]; /* L130: */ } } /* L140: */ } } else if (lsame_(direct, "B")) { for (j = *n - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[i__ + (j + 1) * a_dim1]; a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp * a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = stemp * temp + ctemp * a[ i__ + j * a_dim1]; /* L150: */ } } /* L160: */ } } } else if (lsame_(pivot, "T")) { if (lsame_(direct, "F")) { i__1 = *n; for (j = 2; j <= i__1; ++j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = ctemp * temp - stemp * a[ i__ + a_dim1]; a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + a_dim1]; /* L170: */ } } /* L180: */ } } else if (lsame_(direct, "B")) { for (j = *n; j >= 2; --j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = ctemp * temp - stemp * a[ i__ + a_dim1]; a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + a_dim1]; /* L190: */ } } /* L200: */ } } } else if (lsame_(pivot, "B")) { if (lsame_(direct, "F")) { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { temp = a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1] + ctemp * temp; a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * a_dim1] - stemp * temp; /* L210: */ } } /* L220: */ } } else if (lsame_(direct, "B")) { for (j = *n - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1.f || stemp != 0.f) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { temp = a[i__ + j * a_dim1]; a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1] + ctemp * temp; a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * a_dim1] - stemp * temp; /* L230: */ } } /* L240: */ } } } } return 0; /* End of SLASR */ } /* slasr_ */