--- name: "ddrvrfp" section: "3" platform: "linux" package: "lapack-doc" version: "3.12.1-2" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/ddrvrfp.f" --- # ddrvrfp(3) Part of [ddrvrfp.f(3)](/ddrvrfp.f/3.md). ## NAME TESTING/LIN/ddrvrfp.f ## SYNOPSIS ### Functions/Subroutines subroutine **ddrvrfp** (nout, nn, nval, nns, nsval, nnt, ntval, thresh, a, asav, afac, ainv, b, bsav, xact, x, arf, arfinv, d\_work\_dlatms, d\_work\_dpot01, d\_temp\_dpot02, d\_temp\_dpot03, d\_work\_dlansy, d\_work\_dpot02, d\_work\_dpot03)\ **DDRVRFP** ## Function/Subroutine Documentation ### subroutine ddrvrfp (integer nout, integer nn, integer, dimension( nn ) nval, integer nns, integer, dimension( nns ) nsval, integer nnt, integer, dimension( nnt ) ntval, double precision thresh, double precision, dimension( \* ) a, double precision, dimension( \* ) asav, double precision, dimension( \* ) afac, double precision, dimension( \* ) ainv, double precision, dimension( \* ) b, double precision, dimension( \* ) bsav, double precision, dimension( \* ) xact, double precision, dimension( \* ) x, double precision, dimension( \* ) arf, double precision, dimension( \* ) arfinv, double precision, dimension( \* ) d\_work\_dlatms, double precision, dimension( \* ) d\_work\_dpot01, double precision, dimension( \* ) d\_temp\_dpot02, double precision, dimension( \* ) d\_temp\_dpot03, double precision, dimension( \* ) d\_work\_dlansy, double precision, dimension( \* ) d\_work\_dpot02, double precision, dimension( \* ) d\_work\_dpot03) **DDRVRFP** **Purpose:** ``` !> !> DDRVRFP tests the LAPACK RFP routines: !> DPFTRF, DPFTRS, and DPFTRI. !> !> This testing routine follow the same tests as DDRVPO (test for the full !> format Symmetric Positive Definite solver). !> !> The tests are performed in Full Format, conversion back and forth from !> full format to RFP format are performed using the routines DTRTTF and !> DTFTTR. !> !> First, a specific matrix A of size N is created. There is nine types of !> different matrixes possible. !> 1. Diagonal 6. Random, CNDNUM = sqrt(0.1/EPS) !> 2. Random, CNDNUM = 2 7. Random, CNDNUM = 0.1/EPS !> *3. First row and column zero 8. Scaled near underflow !> *4. Last row and column zero 9. Scaled near overflow !> *5. Middle row and column zero !> (* - tests error exits from DPFTRF, no test ratios are computed) !> A solution XACT of size N-by-NRHS is created and the associated right !> hand side B as well. Then DPFTRF is called to compute L (or U), the !> Cholesky factor of A. Then L (or U) is used to solve the linear system !> of equations AX = B. This gives X. Then L (or U) is used to compute the !> inverse of A, AINV. The following four tests are then performed: !> (1) norm( L*L' - A ) / ( N * norm(A) * EPS ) or !> norm( U'*U - A ) / ( N * norm(A) * EPS ), !> (2) norm(B - A*X) / ( norm(A) * norm(X) * EPS ), !> (3) norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * EPS ), !> (4) ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ), !> where EPS is the machine precision, RCOND the condition number of A, and !> norm( . ) the 1-norm for (1,2,3) and the inf-norm for (4). !> Errors occur when INFO parameter is not as expected. Failures occur when !> a test ratios is greater than THRES. !> ``` **Parameters** *NOUT* ``` !> NOUT is INTEGER !> The unit number for output. !> ``` *NN* ``` !> NN is INTEGER !> The number of values of N contained in the vector NVAL. !> ``` *NVAL* ``` !> NVAL is INTEGER array, dimension (NN) !> The values of the matrix dimension N. !> ``` *NNS* ``` !> NNS is INTEGER !> The number of values of NRHS contained in the vector NSVAL. !> ``` *NSVAL* ``` !> NSVAL is INTEGER array, dimension (NNS) !> The values of the number of right-hand sides NRHS. !> ``` *NNT* ``` !> NNT is INTEGER !> The number of values of MATRIX TYPE contained in the vector NTVAL. !> ``` *NTVAL* ``` !> NTVAL is INTEGER array, dimension (NNT) !> The values of matrix type (between 0 and 9 for PO/PP/PF matrices). !> ``` *THRESH* ``` !> THRESH is DOUBLE PRECISION !> The threshold value for the test ratios. A result is !> included in the output file if RESULT >= THRESH. To have !> every test ratio printed, use THRESH = 0. !> ``` *A* ``` !> A is DOUBLE PRECISION array, dimension (NMAX*NMAX) !> ``` *ASAV* ``` !> ASAV is DOUBLE PRECISION array, dimension (NMAX*NMAX) !> ``` *AFAC* ``` !> AFAC is DOUBLE PRECISION array, dimension (NMAX*NMAX) !> ``` *AINV* ``` !> AINV is DOUBLE PRECISION array, dimension (NMAX*NMAX) !> ``` *B* ``` !> B is DOUBLE PRECISION array, dimension (NMAX*MAXRHS) !> ``` *BSAV* ``` !> BSAV is DOUBLE PRECISION array, dimension (NMAX*MAXRHS) !> ``` *XACT* ``` !> XACT is DOUBLE PRECISION array, dimension (NMAX*MAXRHS) !> ``` *X* ``` !> X is DOUBLE PRECISION array, dimension (NMAX*MAXRHS) !> ``` *ARF* ``` !> ARF is DOUBLE PRECISION array, dimension ((NMAX*(NMAX+1))/2) !> ``` *ARFINV* ``` !> ARFINV is DOUBLE PRECISION array, dimension ((NMAX*(NMAX+1))/2) !> ``` *D\_WORK\_DLATMS* ``` !> D_WORK_DLATMS is DOUBLE PRECISION array, dimension ( 3*NMAX ) !> ``` *D\_WORK\_DPOT01* ``` !> D_WORK_DPOT01 is DOUBLE PRECISION array, dimension ( NMAX ) !> ``` *D\_TEMP\_DPOT02* ``` !> D_TEMP_DPOT02 is DOUBLE PRECISION array, dimension ( NMAX*MAXRHS ) !> ``` *D\_TEMP\_DPOT03* ``` !> D_TEMP_DPOT03 is DOUBLE PRECISION array, dimension ( NMAX*NMAX ) !> ``` *D\_WORK\_DLANSY* ``` !> D_WORK_DLANSY is DOUBLE PRECISION array, dimension ( NMAX ) !> ``` *D\_WORK\_DPOT02* ``` !> D_WORK_DPOT02 is DOUBLE PRECISION array, dimension ( NMAX ) !> ``` *D\_WORK\_DPOT03* ``` !> D_WORK_DPOT03 is DOUBLE PRECISION array, dimension ( NMAX ) !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **232** of file **ddrvrfp.f**. ## Author Generated automatically by Doxygen for LAPACK from the source code.