3. Usage

The corfu package contains functionality to project three-dimensional correlation functions and power spectra along lines of sight to obtain the angular correlation function and angular power spectrum on the sphere. The general process is as follows.

• If you have a 3d power spectrum, such as the matter power spectrum obtained e.g. from CAMB, CLASS, or Eisenstein-Hu, use the corfu.ptoxi() function to obtain the 3d (matter) correlation function.

• If the objective is the computation of an angular power spectrum, use the corfu.theta() function to obtain a set of evaluation points.

• If you have a 3d (matter) correlation function and filter functions along the line of sight, use the corfu.xitow() function to obtain the projected angular correlation function.

• If you have the angular correlation function, use the corfu.wtocl() function to obtain the angular power spectrum.