CGEQL2 man page on Oracle

Man page or keyword search:  
man Server   33470 pages
apropos Keyword Search (all sections)
Output format
Oracle logo
[printable version]

cgeql2.f(3)			    LAPACK			   cgeql2.f(3)

       cgeql2.f -

       subroutine cgeql2 (M, N, A, LDA, TAU, WORK, INFO)
	   CGEQL2 computes the QL factorization of a general rectangular
	   matrix using an unblocked algorithm.

Function/Subroutine Documentation
   subroutine cgeql2 (integerM, integerN, complex, dimension( lda, * )A,
       integerLDA, complex, dimension( * )TAU, complex, dimension( * )WORK,
       CGEQL2 computes the QL factorization of a general rectangular matrix
       using an unblocked algorithm.


	    CGEQL2 computes a QL factorization of a complex m by n matrix A:
	    A = Q * L.


		     M is INTEGER
		     The number of rows of the matrix A.  M >= 0.


		     N is INTEGER
		     The number of columns of the matrix A.  N >= 0.


		     A is COMPLEX array, dimension (LDA,N)
		     On entry, the m by n matrix A.
		     On exit, if m >= n, the lower triangle of the subarray
		     A(m-n+1:m,1:n) contains the n by n lower triangular matrix L;
		     if m <= n, the elements on and below the (n-m)-th
		     superdiagonal contain the m by n lower trapezoidal matrix L;
		     the remaining elements, with the array TAU, represent the
		     unitary matrix Q as a product of elementary reflectors
		     (see Further Details).


		     LDA is INTEGER
		     The leading dimension of the array A.  LDA >= max(1,M).


		     TAU is COMPLEX array, dimension (min(M,N))
		     The scalar factors of the elementary reflectors (see Further


		     WORK is COMPLEX array, dimension (N)


		     INFO is INTEGER
		     = 0: successful exit
		     < 0: if INFO = -i, the i-th argument had an illegal value

	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

	   September 2012

       Further Details:

	     The matrix Q is represented as a product of elementary reflectors

		Q = H(k) . . . H(2) H(1), where k = min(m,n).

	     Each H(i) has the form

		H(i) = I - tau * v * v**H

	     where tau is a complex scalar, and v is a complex vector with
	     v(m-k+i+1:m) = 0 and v(m-k+i) = 1; v(1:m-k+i-1) is stored on exit in
	     A(1:m-k+i-1,n-k+i), and tau in TAU(i).

       Definition at line 124 of file cgeql2.f.

       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2			Tue Sep 25 2012			   cgeql2.f(3)

List of man pages available for Oracle

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net