An n × n Grcar matrix is a nonsymmetric Toeplitz matrix:

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The matrix has sensitive eigenvalues. Figure 1 and Figure 2 are the eigenvalue distribution of 100 by 100 Grcar matrix A and A^{T}, computed by QR algorithm in Matlab.

The following is the FORTRAN calling sequence for forming matrix-vector AX or A^{T}X: Fortran calling sequence.