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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine cgtt02 | ( | character | TRANS, |
integer | N, | ||
integer | NRHS, | ||
complex, dimension( * ) | DL, | ||
complex, dimension( * ) | D, | ||
complex, dimension( * ) | DU, | ||
complex, dimension( ldx, * ) | X, | ||
integer | LDX, | ||
complex, dimension( ldb, * ) | B, | ||
integer | LDB, | ||
real | RESID | ||
) |
CGTT02
CGTT02 computes the residual for the solution to a tridiagonal system of equations: RESID = norm(B - op(A)*X) / (norm(A) * norm(X) * EPS), where EPS is the machine epsilon.
[in] | TRANS | TRANS is CHARACTER Specifies the form of the residual. = 'N': B - A * X (No transpose) = 'T': B - A**T * X (Transpose) = 'C': B - A**H * X (Conjugate transpose) |
[in] | N | N is INTEGTER The order of the matrix A. N >= 0. |
[in] | NRHS | NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0. |
[in] | DL | DL is COMPLEX array, dimension (N-1) The (n-1) sub-diagonal elements of A. |
[in] | D | D is COMPLEX array, dimension (N) The diagonal elements of A. |
[in] | DU | DU is COMPLEX array, dimension (N-1) The (n-1) super-diagonal elements of A. |
[in] | X | X is COMPLEX array, dimension (LDX,NRHS) The computed solution vectors X. |
[in] | LDX | LDX is INTEGER The leading dimension of the array X. LDX >= max(1,N). |
[in,out] | B | B is COMPLEX array, dimension (LDB,NRHS) On entry, the right hand side vectors for the system of linear equations. On exit, B is overwritten with the difference B - op(A)*X. |
[in] | LDB | LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). |
[out] | RESID | RESID is REAL norm(B - op(A)*X) / (norm(A) * norm(X) * EPS) |
Definition at line 126 of file cgtt02.f.