Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?gesc2
Solves a system of linear equations using the LU factorization with complete pivoting computed by ?getc2 .
Syntax
call sgesc2(n, a, lda, rhs, ipiv, jpiv, scale)
call dgesc2(n, a, lda, rhs, ipiv, jpiv, scale)
call cgesc2(n, a, lda, rhs, ipiv, jpiv, scale)
call zgesc2(n, a, lda, rhs, ipiv, jpiv, scale)
Include Files
mkl.fi
Description
The routine solves a system of linear equations
A*X = scale*RHS
with a general n -by- n matrix A using the LU factorization with complete pivoting computed by ?getc2 (Computes the LU factorization with complete pivoting of the general n-by-n matrix.) .
Input Parameters
- n
-
INTEGER. Specifies the order of the matrix A. The value of n must be at least zero.
- a , rhs
-
REAL for sgesc2 DOUBLE PRECISION for dgesc2 COMPLEX for cgesc2 DOUBLE COMPLEX for zgesc2 . Arrays: a(lda,*) contains the LU part of the factorization of the n -by- n matrix A computed by ?getc2 : A = P*L*U*Q . The second dimension of a must be at least max(1, n) ; rhs(n) contains on entry the right hand side vector for the system of equations.
- lda
-
INTEGER . The leading dimension of a ; at least max(1, n) .
- ipiv
-
INTEGER . Array, DIMENSION at least max(1,n) . The pivot indices: for 1 ≤ i ≤ n , row i of the matrix has been interchanged with row ipiv (i) .
- jpiv
-
INTEGER . Array, DIMENSION at least max(1,n) . The pivot indices: for 1 ≤ j ≤ n , column j of the matrix has been interchanged with column jpiv(j) .
Output Parameters
- rhs
-
On exit, overwritten with the solution vector X .
- scale
-
REAL for sgesc2 / cgesc2 DOUBLE PRECISION for dgesc2 / zgesc2 Contains the scale factor. scale is chosen in the range 0 ≤ scale ≤ 1 to prevent overflow in the solution.