109 SUBROUTINE sgetf2( M, N, A, LDA, IPIV, INFO )
117 INTEGER INFO, LDA, M, N
128 parameter ( one = 1.0e+0, zero = 0.0e+0 )
137 EXTERNAL slamch, isamax
152 ELSE IF( n.LT.0 )
THEN
154 ELSE IF( lda.LT.max( 1, m ) )
THEN
158 CALL xerbla(
'SGETF2', -info )
164 IF( m.EQ.0 .OR. n.EQ.0 )
171 DO 10 j = 1, min( m, n )
175 jp = j - 1 + isamax( m-j+1, a( j, j ), 1 )
177 IF( a( jp, j ).NE.zero )
THEN
182 $
CALL sswap( n, a( j, 1 ), lda, a( jp, 1 ), lda )
187 IF( abs(a( j, j )) .GE. sfmin )
THEN
188 CALL sscal( m-j, one / a( j, j ), a( j+1, j ), 1 )
191 a( j+i, j ) = a( j+i, j ) / a( j, j )
196 ELSE IF( info.EQ.0 )
THEN
201 IF( j.LT.min( m, n ) )
THEN
205 CALL sger( m-j, n-j, -one, a( j+1, j ), 1, a( j, j+1 ), lda,
206 $ a( j+1, j+1 ), lda )
subroutine sger(M, N, ALPHA, X, INCX, Y, INCY, A, LDA)
SGER
subroutine sgetf2(M, N, A, LDA, IPIV, INFO)
SGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row inter...
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine sscal(N, SA, SX, INCX)
SSCAL
subroutine sswap(N, SX, INCX, SY, INCY)
SSWAP