*** Evolving the Linear Matter Power Spectrum ***
January 2, 2011: E.Komatsu

This program evolves the input power spectrum data at a given redshift, zin,
to that at a different redshift, zout, by multiplying the appropriate linear
growth factor, D(z).

P(k,zout) = P(k,zin) * [D(zout)/D(zin)]^2

Or, in terms of g(z)=(1+z)D(z),

P(k,zout) = P(k,zin) * [g(zout)/g(zin)]^2 * [(1+zin)/(1+zout)]^2

As input power spectrum data, "wmap5baosn_max_likelihood_matterpower.dat,"
which was generated using CAMB code for the maximum likelihood parameters
given in Table I of Komatsu et al.(2008) [WMAP 5-year interpretation paper] with 
"WMAP5+BAO+SN". The input file for CAMB is also provided 
(wmap5baosn_max_likelihood_params.ini). NOTE THAT THIS POWER SPECTRUM IS COMPUTED AT Z=0.

- To compile and use the sample programs (given below), edit Makefile
and simply "make"
- It will generate an executable "evolve_linearpk", which reads in the 
power spectrum file, and evolves the power spectrum data to a redshift
of your choice, and writes out the result as "evolved_linearpk.txt"

A sample power spectrum, evolved back to z=30, is provided as 
"wmap5baosn_max_likelihood_matterpower_at_z=30.dat". You can check to see
if your result agrees with this file.