This is a repository with ways to calculate the cohomology of real grassmannians.
There is a Mathematica Notebook which, after inputting k and n (in regards to Gr_k(n), the k-planes in R^n), gives you a list of numbers (0,2,-2) and their corresponding map between cellular chain groups in the Grassmannian (using the Schubert cells).
This was helpful in the calculations required in the following arXiv paper which was joint work with Eric Berry.
See the folder example-calculations for example calculations with the notebook.
I will add instructions on how to put this into CHOMP to get the actual cohomology groups out of this soon.