==GenPK==

This is GenPK, a program to calculate the 3D matter power spectrum. 

To build, first make sure FFTW3 is installed on your system
and that the headers are in your PATH.

To build, type:

make

For the test suite (requires Boost::Test > 1.34), do: 

make test

To run, do:

 ./gen-pk -i filename -o outputdir

filename can be any Gadget snapshot, with or without the .o, in format I or II.

For the doxygen-generated documentation, do:

make doc

To delete compiler output:

make clean

Further documentation may be found in the doxygen generated files in doc/html/index.html
(type "make doc" to make this file), by typing ./gen-pk --help or in gen-pk.cpp

Powerspectrum output is in Fourier units; to convert to, eg, Mpc/h, you should multiply 
k by 2 \pi / Boxsize and P(k) by (Boxsize/2\pi)^3, 
where Boxsize is the size of the box in Mpc/h.

In addition, CAMB uses a different Fourier convention to FFTW (which GenPK is based on), 
so for comparison to CAMB you need to also multiply P(k) by (2\pi) ^3. 
The total conversion factors are then

k *= 2\pi / Boxsize
P(k) *= Boxsize ^3

A script to do this can be found in plot.py

If you use this software in a paper, you can cite it via the ASCL:
http://ascl.net/1706.006