Introducing dark energy with evolving energy density to the code

[Cihad Kıbrıs]

I want to modify the CLASS/CAMB so that it accommodates a new form of dark energy with varying energy density, that is [math]\rho_{\rm DE}(a) = \rho_{\rm DE, 0} f(a) where [math]f(a) encodes the time evolution of the dark energy density. What should I exactly modify in the code to incorporate this kind of source?

[Antony Lewis]

If you can calculate w(a), you can use as in box 13 of the example notebook
https://camb.readthedocs.io/en/latest/CAMBdemo.html