home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Turnbull China Bikeride
/
Turnbull China Bikeride - Disc 1.iso
/
ARGONET
/
PD
/
MATHS
/
RLAB
/
RLAB125.ZIP
/
!RLaB
/
help_ai
/
factor
< prev
next >
Wrap
Text File
|
1994-09-04
|
1KB
|
39 lines
factor:
Syntax: factor ( A )
factor ( A , TYPE )
Description:
The factor function computes the LU factorization of the input
matrix A. Factor returns a list with 3 elements:
if A is a general matrix:
lu a matrix containing the LU factors
pvt a vector containing the pivot indices
rcond the inverse of the condition estimate
Factor utilizes the LAPACK subroutines DGETRF, DGECON or
ZGETRF, ZGECON.
if A is a symmetric matrix:
ldl a matrix containing the block diagonal matrix
D, and the multipliers used to obtain L.
pvt a vector containing the pivot indices
rcond the inverse of the condition estimate
Factor utilizes the LAPACK subroutines DSYTRF, DSYCON or
ZHETRF, ZHECON.
The user can overide factor's choice of solution type with the
optional argument TYPE.
TYPE = "g" or "G" The general solution is used.
TYPE = "s" or "S" the symmetric solution is used.
Factor returns the results in the above format, so that they
may be conveniently used with backsub for repetitive
solutions. The user-function lu will separate the results from
factor into separate L and U matrices.
See Also: backsub, inv, lu, solve