Visible to Intel only — GUID: GUID-66F60167-A653-4DC5-BAF4-D003BBBAA746
Visible to Intel only — GUID: GUID-66F60167-A653-4DC5-BAF4-D003BBBAA746
?dttrsb
Solves a system of linear equations with a diagonally dominant tridiagonal coefficient matrix using the LU factorization computed by ?dttrfb.
Syntax
call sdttrsb( trans, n, nrhs, dl, d, du, b, ldb, info )
call ddttrsb( trans, n, nrhs, dl, d, du, b, ldb, info )
call cdttrsb( trans, n, nrhs, dl, d, du, b, ldb, info )
call zdttrsb( trans, n, nrhs, dl, d, du, b, ldb, info )
call dttrsb( dl, d, du, b [, trans] [, info] )
Include Files
- mkl.fi, lapack.f90
Description
The ?dttrsb routine solves the following systems of linear equations with multiple right hand sides for X:
A*X = B |
if trans='N', |
AT*X = B |
if trans='T', |
AH*X = B |
if trans='C' (for complex matrices only). |
Before calling this routine, call ?dttrfb to compute the factorization of A.
Input Parameters
trans |
CHARACTER*1. Must be 'N' or 'T' or 'C'. Indicates the form of the equations solved for X: If trans = 'N', then A*X = B. If trans = 'T', then AT*X = B. If trans = 'C', then AH*X = B. |
n |
INTEGER. The order of A; n≥ 0. |
nrhs |
INTEGER. The number of right-hand sides, that is, the number of columns in B; nrhs≥ 0. |
dl, d, du, b |
REAL for sdttrsb DOUBLE PRECISION for ddttrsb COMPLEX for cdttrsb DOUBLE COMPLEX for zdttrsb. Arrays: dl(n -1), d(n), du(n -1), b(ldb,nrhs). The array dl contains the (n - 1) multipliers that define the matrices L1, L2 from the factorization of A. The array d contains the n diagonal elements of the upper triangular matrix U from the factorization of A. The array du contains the (n - 1) elements of the superdiagonal of U. The array b contains the matrix B whose columns are the right-hand sides for the systems of equations. |
ldb |
INTEGER. The leading dimension of b; ldb≥ max(1, n). |
Output Parameters
b |
Overwritten by the solution matrix X. |
info |
INTEGER. If info = 0, the execution is successful. If info = -i, the i-th parameter had an illegal value. |