202 SUBROUTINE cunbdb1( M, P, Q, X11, LDX11, X21, LDX21, THETA, PHI,
203 $ taup1, taup2, tauq1, work, lwork, info )
211 INTEGER INFO, LWORK, M, P, Q, LDX11, LDX21
214 REAL PHI(*), THETA(*)
215 COMPLEX TAUP1(*), TAUP2(*), TAUQ1(*), WORK(*),
216 $ x11(ldx11,*), x21(ldx21,*)
223 parameter( one = (1.0e0,0.0e0) )
227 INTEGER CHILDINFO, I, ILARF, IORBDB5, LLARF, LORBDB5,
240 INTRINSIC atan2, cos, max, sin, sqrt
247 lquery = lwork .EQ. -1
251 ELSE IF( p .LT. q .OR. m-p .LT. q )
THEN
253 ELSE IF( q .LT. 0 .OR. m-q .LT. q )
THEN
255 ELSE IF( ldx11 .LT. max( 1, p ) )
THEN
257 ELSE IF( ldx21 .LT. max( 1, m-p ) )
THEN
263 IF( info .EQ. 0 )
THEN
265 llarf = max( p-1, m-p-1, q-1 )
268 lworkopt = max( ilarf+llarf-1, iorbdb5+lorbdb5-1 )
271 IF( lwork .LT. lworkmin .AND. .NOT.lquery )
THEN
275 IF( info .NE. 0 )
THEN
276 CALL xerbla(
'CUNBDB1', -info )
278 ELSE IF( lquery )
THEN
286 CALL clarfgp( p-i+1, x11(i,i), x11(i+1,i), 1, taup1(i) )
287 CALL clarfgp( m-p-i+1, x21(i,i), x21(i+1,i), 1, taup2(i) )
288 theta(i) = atan2(
REAL( X21(I,I) ),
REAL( X11(I,I) ) )
293 CALL clarf(
'L', p-i+1, q-i, x11(i,i), 1, conjg(taup1(i)),
294 $ x11(i,i+1), ldx11, work(ilarf) )
295 CALL clarf(
'L', m-p-i+1, q-i, x21(i,i), 1, conjg(taup2(i)),
296 $ x21(i,i+1), ldx21, work(ilarf) )
299 CALL csrot( q-i, x11(i,i+1), ldx11, x21(i,i+1), ldx21, c,
301 CALL clacgv( q-i, x21(i,i+1), ldx21 )
302 CALL clarfgp( q-i, x21(i,i+1), x21(i,i+2), ldx21, tauq1(i) )
303 s =
REAL( X21(I,I+1) )
305 CALL clarf(
'R', p-i, q-i, x21(i,i+1), ldx21, tauq1(i),
306 $ x11(i+1,i+1), ldx11, work(ilarf) )
307 CALL clarf(
'R', m-p-i, q-i, x21(i,i+1), ldx21, tauq1(i),
308 $ x21(i+1,i+1), ldx21, work(ilarf) )
309 CALL clacgv( q-i, x21(i,i+1), ldx21 )
310 c = sqrt( scnrm2( p-i, x11(i+1,i+1), 1, x11(i+1,i+1),
311 $ 1 )**2 + scnrm2( m-p-i, x21(i+1,i+1), 1, x21(i+1,i+1),
313 phi(i) = atan2( s, c )
314 CALL cunbdb5( p-i, m-p-i, q-i-1, x11(i+1,i+1), 1,
315 $ x21(i+1,i+1), 1, x11(i+1,i+2), ldx11,
316 $ x21(i+1,i+2), ldx21, work(iorbdb5), lorbdb5,
subroutine csrot(N, CX, INCX, CY, INCY, C, S)
CSROT
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine cunbdb1(M, P, Q, X11, LDX11, X21, LDX21, THETA, PHI, TAUP1, TAUP2, TAUQ1, WORK, LWORK, INFO)
CUNBDB1
subroutine cunbdb5(M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2, LDQ2, WORK, LWORK, INFO)
CUNBDB5
subroutine clacgv(N, X, INCX)
CLACGV conjugates a complex vector.
subroutine clarfgp(N, ALPHA, X, INCX, TAU)
CLARFGP generates an elementary reflector (Householder matrix) with non-negatibe beta.
subroutine clarf(SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
CLARF applies an elementary reflector to a general rectangular matrix.