Abstract
MuPAT enables the users to easily treat quadruple and octuple precision arithmetics as well as double precision arithmetic on Scilab. Using external C routines, we have also developed a high speed implementation MuPAT_c for Windows, Mac OS, and Linux. MuPAT_c reduced the computation time especially for all octuple precision arithmetic and inner product of quadruple precision arithmetic. MuPAT_c can run 90-1200 times faster than MuPAT. We applied three different precisions to tridiagonalization by the Lanczos method and confirmed that a high precision arithmetic was essential for the Lanczos method to get accurate eigenvalues of real symmetric matrices.
