Tests for the ScaLAPACK INV routines

The inversion test driver tests five different matrix types - general nonsymmetric (GEN), general upper or lower triangular (UTR and LTR), and symmetric positive definite (upper or lower triangular) (UPD or LPD).

• If GEN, compute the LU factorization using PxGETRF, and then compute the inverse by invoking PxGETRI
• If UTR or LTR, set UPLO='U' or UPLO='L' respectively, and compute the inverse by invoking PxTRTRI
• If UPD or LPD, set UPLO='U' or UPLO='L' respectively, compute the Cholesky factorization using PxPOTRF, and then compute the inverse by invoking PxPOTRI
• Compute the ratio
  • FRESID $= \vert\vert A A^{-1} - I \vert\vert / ( n \vert\vert A \vert\vert \varepsilon )$