Fisher Matrices and Confidence Ellipses: A Quick-Start Guide and
  Software
  Fisher matrices are used frequently in the analysis of combining cosmological
constraints from various data sets. They encode the Gaussian uncertainties of
multiple variables. They are simple to use, and I show how to get up and
running with them quickly. Python software is also provided. I cover how to
obtain confidence ellipses, add datasets, apply priors, marginalize, transform
variables, and even calculate your own Fisher matrices. This treatment is not
new, but I aim to provide a clear and concise reference guide. I also provide
references and links to more sophisticated treatments and software.
