CSYL01 tests CTRSYL and CTRSYL3, routines for solving the Sylvester matrix


 equation


    op(A)*X + ISGN*X*op(B) = scale*C,


 where op(A) and op(B) are both upper triangular form, op() represents an


 optional conjugate transpose, and ISGN can be -1 or +1. Scale is an output


 less than or equal to 1, chosen to avoid overflow in X.


 The test code verifies that the following residual does not exceed


 the provided threshold:


    norm(op(A)*X + ISGN*X*op(B) - scale*C) /


        (EPS*max(norm(A),norm(B))*norm(X))


 This routine complements CGET35 by testing with larger,


 random matrices, of which some require rescaling of X to avoid overflow.

THRESH

          THRESH is REAL


          A test will count as 'failed' if the residual, computed as


          described above, exceeds THRESH.

NFAIL

          NFAIL is INTEGER array, dimension (3)


          NFAIL(1) = No. of times residual CTRSYL exceeds threshold THRESH


          NFAIL(2) = No. of times residual CTRSYL3 exceeds threshold THRESH


          NFAIL(3) = No. of times CTRSYL3 and CTRSYL deviate

RMAX

          RMAX is DOUBLE PRECISION array, dimension (2)


          RMAX(1) = Value of the largest test ratio of CTRSYL


          RMAX(2) = Value of the largest test ratio of CTRSYL3

NINFO

          NINFO is INTEGER array, dimension (2)


          NINFO(1) = No. of times CTRSYL where INFO is nonzero


          NINFO(2) = No. of times CTRSYL3 where INFO is nonzero

KNT

          KNT is INTEGER


          Total number of examples tested.