128 RECURSIVE SUBROUTINE dgelqt3( M, N, A, LDA, T, LDT, INFO )
135 INTEGER info, lda, m, n, ldt
138 DOUBLE PRECISION a( lda, * ), t( ldt, * )
145 parameter( one = 1.0d+00 )
148 INTEGER i, i1, j, j1, m1, m2, iinfo
158 ELSE IF( n .LT. m )
THEN
160 ELSE IF( lda .LT. max( 1, m ) )
THEN
162 ELSE IF( ldt .LT. max( 1, m ) )
THEN
166 CALL xerbla(
'DGELQT3', -info )
174 CALL dlarfg( n, a( 1, 1 ), a( 1, min( 2, n ) ), lda,
188 CALL dgelqt3( m1, n, a, lda, t, ldt, iinfo )
194 t( i+m1, j ) = a( i+m1, j )
197 CALL dtrmm(
'R',
'U',
'T',
'U', m2, m1, one,
198 & a, lda, t( i1, 1 ), ldt )
200 CALL dgemm(
'N',
'T', m2, m1, n-m1, one, a( i1, i1 ), lda,
201 & a( 1, i1 ), lda, one, t( i1, 1 ), ldt)
203 CALL dtrmm(
'R',
'U',
'N',
'N', m2, m1, one,
204 & t, ldt, t( i1, 1 ), ldt )
206 CALL dgemm(
'N',
'N', m2, n-m1, m1, -one, t( i1, 1 ), ldt,
207 & a( 1, i1 ), lda, one, a( i1, i1 ), lda )
209 CALL dtrmm(
'R',
'U',
'N',
'U', m2, m1 , one,
210 & a, lda, t( i1, 1 ), ldt )
214 a( i+m1, j ) = a( i+m1, j ) - t( i+m1, j )
221 CALL dgelqt3( m2, n-m1, a( i1, i1 ), lda,
222 & t( i1, i1 ), ldt, iinfo )
228 t( j, i+m1 ) = (a( j, i+m1 ))
232 CALL dtrmm(
'R',
'U',
'T',
'U', m1, m2, one,
233 & a( i1, i1 ), lda, t( 1, i1 ), ldt )
235 CALL dgemm(
'N',
'T', m1, m2, n-m, one, a( 1, j1 ), lda,
236 & a( i1, j1 ), lda, one, t( 1, i1 ), ldt )
238 CALL dtrmm(
'L',
'U',
'N',
'N', m1, m2, -one, t, ldt,
241 CALL dtrmm(
'R',
'U',
'N',
'N', m1, m2, one,
242 & t( i1, i1 ), ldt, t( 1, i1 ), ldt )
subroutine dgemm(transa, transb, m, n, k, alpha, a, lda, b, ldb, beta, c, ldc)
DGEMM