Guide to PETSc Quick Start Tutorial on Time, Accuracy, Speed Analysis(TAS)#

Below is the guide to running TAS using ex13, which is a Poisson Problem in 2D and 3D with Finite Elements:

  1. Compile ex13.c

  1. This file is located in PETSC_DIR/src/snes/tutorials/

  2. If you do not know how to build a PETSc code here is an example makefile

    include ${PETSC_DIR}/lib/petsc/conf/variables
include ${PETSC_DIR}/lib/petsc/conf/rules

ex13: ex13.o
	${CLINKER} -o $@ $^ ${PETSC_LIB}

  1. Run ex13 with the following command:

    mpiexec -n 2 ./ex13 -log_view :/home/<user name>/PETSC_DIR/lib/petsc/bin/ex_13_test.py:ascii_info_detail \
  -dm_distribute \
  -dm_plex_box_faces 8,8 \
  -potential_petscspace_degree 1 \
  -snes_convergence_estimate \
  -convest_num_refine 5

  2. A log file in the above directory called ex_13_test.py should now be present. This is also the same directory that contains the TAS python3 script petsc_tas_analysis.py

  3. Now run petsc_tas_analysis.py:

    ./petsc_tas_analysis.py -f ex_13_test

  4. You should see something similar to the following in your terminal window:

    ex_13Test
		*******************Data for ex_13Test***************************
              Times : [0.007 0.019 0.045 0.136 0.49 ]

          Mean Time : [0.007 0.019 0.045 0.136 0.49 ]

        Times Range : [3.87e-06 4.20e-06 4.40e-06 4.00e-06 3.00e-06]

   Time Growth Rate : [2.84  2.361 3.029 3.591]

              Flops : [1.834e+04 1.443e+05 8.816e+05 7.164e+06 6.256e+07]

         Mean Flops : [9.168e+03 7.215e+04 4.408e+05 3.582e+06 3.128e+07]

         Flop Range : [9.691e+03 7.644e+04 4.595e+05 3.677e+06 3.174e+07]

   Flop Growth Rate : [7.87  6.109 8.126 8.733]

          LU Factor : [7.157e-06 2.878e-05 7.875e-05 2.821e-04 1.050e-03]

     LU Factor Mean : [6.480e-06 2.694e-05 7.535e-05 2.702e-04 1.048e-03]

    LU Factor Range : [1.354e-06 3.668e-06 6.786e-06 2.368e-05 4.970e-06]

 LU Factor Growth Rate : []

**********Data for Field 0************
               dofs : [  12.   56.  240.  992. 4032.]

             Errors : [0.203 0.053 0.013 0.003 0.001]

Least Squares Data
==================
Mesh Convergence
Alpha: -0.9460821998182669 
  0.3575225062079136
convRate: 1.8921643996365338 of ex_13Test data

  5. Finally the graphs will appear in the subdirectory graphs/

For more detailed help in using TAS:

  1. See detailed user’s guide

  2. On the command line use ./petsc_tas_analysis.py -h