.. _first_run: Running an example ================== Many examples of Clawpack simulations can be seen in the :ref:`galleries`. See also :ref:`first_tests`. PyClaw ------ To run an example and plot the results using PyClaw, simply do the following (starting from your `clawpack` directory):: cd pyclaw/examples/euler_2d python shock_bubble_interaction.py iplot=1 That's it. For next steps with PyClaw, see :ref:`basics`. Classic ------- First ensure that you have :ref:`setenv` and that you have the :ref:`install_prerequisites`. A simple 1-dimensional acoustics equations can be solved using the code in `$CLAW/classic/examples/acoustics_1d_example1 `__, as illustrated in the `Gallery of Classic and AMRClaw applications `__ Move to this directory via:: cd $CLAW/classic/examples/acoustics_1d_example1 You can try the following test in this directory, or you may want to first make a copy of it (see the instructions in :ref:`copyex`). The Makefiles are set up to do dependency checking so that in many application directories you can simply type:: $ make .plots and the Fortran code will be compiled, data files created, the code run, and the results plotted automatically, resulting in a set of webpages showing the results. However, if this is your first attempt to run a code, it is useful to go through these steps one at a time, both to understand the steps and so that any problems with your installation can be properly identified. You might want to start by examining the Makefile. This sets a number of variables, which at some point you might need to modify for other examples, see :ref:`makefiles` for more about this. At the bottom of the Makefile is an `include` statement that points to a common Makefile that is used by most applications, and where all the details of the make process can be found. To compile the code, type:: $ make .exe If this gives an error, see :ref:`trouble_makeexe`. This should compile the example code (after first compiling the required library routines) and produce an executable named `xclaw` in this directory. Before running the code, it is necessary to also create a set of data files that are read in by the Fortran code. This can be done via:: $ make .data If this gives an error, see :ref:`trouble_makedata`. This uses the Python code in `setrun.py` to create data files that have the form `*.data`. Once the executable and the data files all exist, we can run the code. The recommended way to do this is to type:: $ make .output If this gives an error, see :ref:`trouble_makeoutput`. Before running the code a subdirectory `_output` is created and the output of the code (often a large number of files) is directed to this subdirectory. This is convenient if you want to do several runs with different parameter values and keep the results organized. After the code has run you can rename the subdirectory, or you can modify the variable `OUTDIR` in the Makefile to direct results to a different directory. See :ref:`makefiles` for more details. Copies of all the data files are also placed in the output directory for future reference. **Plotting the results.** Once the code has run and the files listed above have been created, there are several options for plotting the results. To try the Python tools, type:: $ make .plots If this gives an error, see :ref:`trouble_makeplots`. If this works, it will create a subdirectory named `_plots` that contains a number of image files (the `*.png` files) and a set of html files that can be used to view the results from a web browser. See :ref:`plotting_makeplots` for more details. An alternative is to view the plots from an interactive Python session, as described in the section :ref:`plotting_Iplotclaw`. If you wish to use Matlab instead, see :ref:`matlabplots`. Other visualization packages could also be used to display the results, but you will need to figure out how to read in the data. See :ref:`fortfiles` for information about the format of the files produced by Clawpack.