A cosmological power spectrum calculation implemented in Rust.
Calculates the cross-power spectrum of two cosmological fields (or, if the fields are the same, the auto-power spectrum).
Credit to Girish Kulkarni for the underlying algorithm. Uses the fftw crate as a wrapper to the FFTW3 C library.
Requires an installation of Rust, and the fftw crate requires a C compiler and make to compile the underlying source for the library. With those prerequisites, installation should be as simple as cloning the repository and using cargo build:
$ curl https://sh.rustup.rs -sSf | sh # install Rust
$ git clone https://github.com/lewis-weinberger/crosscorr # clone repository
$ cd crosscorr # change into source directory
$ cargo build --release # compile release version
Note compiling the release version will take longer but provides considerable optimisation -- this speeds up the code dramatically (in particular the file IO).
crosscorr is designed to take as input two three-dimensional uniformly gridded fields (stored as row-major 1D arrays). The executable reads in the configuration from a RON file laid out as follows:
// config.ron
(
grid1_filename: "/path/to/grid1",
grid2_filename: "/path/to/grid2",
output_filename: "/path/to/output",
ngrid: 2048,
boxsize: 160,
)
where the filename fields are strings containing the paths to the data, and
the desired output location; ngrid is the number of cells on a side for the
3D data cubes; boxsize is the physical length of the data cube. Note the data fields should be the same size (i.e. same number of grid cells on a side).
To run the program from the root cargo directory use:
$ cargo run config.ron
where config.ron is the configuration file explained above. If you have not compiled the executable then this command will compile it before running. The program will print to stdout/sterr as it progresses.
To deconvolve either a nearest-grid-point (NGP) or cloud-in-cell (CIC) mass-assignment for one of the fields, you can pass a feature flag:
$ cargo build --release --features=ngp_correction_single
or
$ cargo build --release --features=cic_correction_single
(substitute both for single if you want to correct both fields).