Zgebak Zgebal Zgehrd Zhsein Zhseqr Ztrevc3 Ztrexc Ztrsen Ztrsna Ztrsyl Zunghr Zunmhr

Ztrsyl() Sub Ztrsyl ( Transa As  String, Transb As  String, Isign As  Long, M As  Long, N As  Long, A() As  Complex, B() As  Complex, C() As  Complex, Scal As  Double, Info As  Long  ) Solve complex Sylvester matrix equation Purpose This routine solves the complex Sylvester matrix equation: op(A)*X + X*op(B) = scale*C or op(A)*X - X*op(B) = scale*C where op(A) = A or A^H, and A and B are both upper quasi-triangular. A is M x M and B is N x N. The right hand side C and the solution X are M x N. scale is an output scale factor, set <= 1 by the routine to avoid overflow in X. Parameters [in] Transa Specifies the option op(A): = "N": op(A) = A (No transpose) = "C": op(A) = A^H (Conjugate transpose) [in] Transb Specifies the option op(B): = "N": op(B) = B (No transpose) = "C": op(B) = B^H (Conjugate transpose) [in] Isgn Specifies the sign in the equation: = +1: Solve op(A)*X + X*op(B) = scale*C = -1: Solve op(A)*X - X*op(B) = scale*C [in] M The order of the matrix A, and the number of rows in the matrices X and C. (M >= 0) (If M = 0, returns without computation) [in] N The order of the matrix B, and the number of columns in the matrices X and C. (N >= 0) (If N = 0, returns without computation) [in] A() Array A(LA1 - 1, LA2 - 1) (LA1 >= M, LA2 >= M) The upper triangular matrix A. [in] B() Array B(LB1 - 1, LB2 - 1) (LB1 >= N, LB2 >= N) The upper triangular matrix B. [in,out] C() Array C(LC1 - 1, LC2 - 1) (LC1 >= M, LC2 >= N) [in] The M x N right hand side matrix C. [out] Overwritten by the solution matrix X. [out] Scal The scale factor, scale, set <= 1 by the routine to avoid overflow in X. [out] Info = 0: Successful exit. = -1: The argument Transa had an illegal value. (Transa <> "N" nor "C") = -2: The argument Transb had an illegal value. (Transb <> "N" nor "C") = -3: The argument Isgn had an illegal value. (Isign <> 1 nor -1) = -4: The argument M had an illegal value. (M < 0) = -5: The argument N had an illegal value. (N < 0) = -6: The argument A() is invalid. = -7: The argument B() is invalid. = -8: The argument C() is invalid. = 1: A and B have common or very close eigenvalues; perturbed values were used to solve the equation (but the matrices A and B are unchanged). Reference LAPACK