This program is a spiritual successor to the map.m program produced by Michael Dellnitz c. 1995, which was in turn adapted from the pplane5.m code by John Polking. The code will take polygons and matrices from .ini files, load them, and then use matplotlib to show the effect of a selected matrix as a linear transformation on the selected polygon. Python tkinter and matplotlib are is used to create the GUI, while numpy is used on the back end for calculations. See pymap.py for formatting information for the .ini files if you want to add new polygons or matrices to the program when it loads.
Use of this program requires a Python 3 intepreter with the packages numpy, matplotlib, and tkinter installed. The tkinter package is included in most Python distributions by default, but you may need to install the others separately.
If you install the default Python 3.6.6 distribution from Python.org, it should come with a package manager called pip, which you can use to install these other packages. To install them, you can type
pip install numpy matplotlib
in your shell/command prompt once you've installed Python 3. To run the program, open a command prompt in the directory that your pymap.py is located and enter
python pymap.py
As an alternative, the Anaconda distribution of Python 3.6 from anaconda.com includes these packages and much more, obviating the need for pip in this instance. If you use this, open pymap.py in the Spyder program that comes with the distribution and click the green arrow. If you want to run it outside of Spyder, you may have to run it from the Anaconda Prompt that comes with the distribution instead (it works just like your standard command prompt).
From the dropdown menus, you can select named polygons and matrices to see the effect of a given matrix on a polygon. If you want to use your own matrix, just enter entries into the "Matrix entries" fields and click the Refresh button. If you place an unused name in the "Name your matrix" field, the application will add your matrix to the list of matrices for the current session (new matrices will be lost when you close the application, so you should put them in the matrices.ini file if it is important to you that they be around for next time). You may translate your polygon around the pymap plot, either by changing the values in the "Translate this polygon by" fields or by clicking on the plot. Resizing the application window should only change the size of the plot, and not the UI. If you would like to change the appearance of the application, some variables in the PyMapApp class allow for this. If the program reacts to your input in a way that you did not expect, check the names in the matrix and polygon pulldown menus to see if there are any error messages. If you click in the plot canvas, but not on the plot itself, pymap will transform your last transformed polygon and plot it with a random color.
Tip: if you remove one of the .ini files from pymap's working directory, the program will recreate the .ini files that you see in this repository.