LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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subroutine sget31 | ( | real | RMAX, |
integer | LMAX, | ||
integer, dimension( 2 ) | NINFO, | ||
integer | KNT | ||
) |
SGET31
SGET31 tests SLALN2, a routine for solving (ca A - w D)X = sB where A is an NA by NA matrix (NA=1 or 2 only), w is a real (NW=1) or complex (NW=2) constant, ca is a real constant, D is an NA by NA real diagonal matrix, and B is an NA by NW matrix (when NW=2 the second column of B contains the imaginary part of the solution). The code returns X and s, where s is a scale factor, less than or equal to 1, which is chosen to avoid overflow in X. If any singular values of ca A-w D are less than another input parameter SMIN, they are perturbed up to SMIN. The test condition is that the scaled residual norm( (ca A-w D)*X - s*B ) / ( max( ulp*norm(ca A-w D), SMIN )*norm(X) ) should be on the order of 1. Here, ulp is the machine precision. Also, it is verified that SCALE is less than or equal to 1, and that XNORM = infinity-norm(X).
[out] | RMAX | RMAX is REAL Value of the largest test ratio. |
[out] | LMAX | LMAX is INTEGER Example number where largest test ratio achieved. |
[out] | NINFO | NINFO is INTEGER array, dimension (2) NINFO(1) = number of examples with INFO less than 0 NINFO(2) = number of examples with INFO greater than 0 |
[out] | KNT | KNT is INTEGER Total number of examples tested. |