Quick tests of the installation¶

Once you’re done with the installation, a few tests can confirm that PISM is functioning correctly.

Try a MPI four process verification run:
```
mpiexec -n 4 pismv -test G -y 200
```
If you see some output and a final Writing model state to file ’unnamed.nc’ then PISM completed successfully. At the end of this run you get measurements of the difference between the numerical result and the exact solution. See Verification for more on PISM verification.

The above “-n 4” run should work even if there is only one actual processor (core) on your machine. (In that case MPI will just run multiple processes on the one processor.) This run will also produce a NetCDF output file unnamed.nc, which can be read and viewed by NetCDF tools.
Try an EISMINT II run using the PETSc viewers (under the X window system):
```
pismr -eisII A -y 5000 -view thk,temppabase,velsurf_mag
```
When using such viewers and mpiexec the additional final option -display :0 is sometimes required to enable MPI to use X, like this:
```
mpiexec -n 2 pismr -eisII A -y 5000 -view thk,temppabase,velsurf_mag -display :0
```
Also -drawpause 0.1 or similar may be needed if the figures are refreshing too fast.
Run a basic suite of software tests. To do this, make sure that NCO and Python packages NumPy and netcdf4-python are installed. Also, the CMake flag Pism_BUILD_EXTRA_EXECS should be ON. Then run:
```
make       # do this if you changed something with CMake
make test
```
in the build directory.

The message at the bottom of the output should say

100% tests passed, 0 tests failed out of XX

or similar.

Feel free to e-mail us about any test failures you see. Please run
```
ctest --output-on-failure > make-test.log
```
and send us the make-test.log that this produces.

Next steps¶

Start with the section Getting started: a Greenland ice sheet example.

Completely up-to-date documentation can be built from source; see Rebuilding PISM documentation for details.

A final reminder with respect to installation: Let’s assume you have checked out a copy of PISM using Git, as described above. You can then update your copy of PISM to the latest version by running git pull in the PISM directory and make install in your build directory.