A direct estimator of the bispectrum
This is a parallelized code for the calculation of the Spherically Averaged Bispectrum (SABS). It is based on a new optimised direct estimation method and written in C.
The user is referred to section 2 of Mondal et al. 2021 (https://arxiv.org/abs/2107.02668) for a detailed description of the algorithm.
Download the code by cloning the git repository using
$ git clone https://github.com/rajeshmondal18/DviSukta
The code starts by reading the real space gridded data and performing a 3D Fourier transform of it. Alternatively, it starts by reading the data already in Fourier space.
If your data is in real space, you need to install FFTW-3.x.x with the following flags: '--enable-float', '--enable-threads' and '--enable-openmp' to compile this set of codes. Look at the installation instruction http://www.fftw.org/fftw3_doc/Installation-on-Unix.html#Installation-on-Unix
Use the makefile for compilation in the following manner:
$ make
It will create the executable 'bispec'.
You need to specify
- Grid spacing in Mpc
- The number of k1 bins
- The number of n bins
- The number of cos(theta) bins
in the input file.
An input data "c_data8.0_100" (binary data) and an input file "input.bispec" have been provided for testing.
To run:
$ ./bispec
Please acknowledge Mondal et al. 2021 (https://arxiv.org/abs/2107.02668) if you are using this code.