README - July, 2012

nfftls is a program for fast computing Lomb-Scargle periodograms.

The present archive contains an example of C implementation of the
code described in 

  B. Leroy,

  "Fast calculation of the Lomb-Scargle periodogram using
   nonequispaced fast Fourier transform"

  Astron. Astrophys. 545, A50 (2012)
  DOI: http://dx.doi.org/10.1051/0004-6361/201219076 

For the benefit of the scientific community, the ISO-C source is published
under the GNU General Public License 3 (see COPYING file).

I you use this program in your research work, I would appreciate your
citing the above reference.

1) Prerequisites 

* The following libraries must have been installed:

  - FFTW3 library (http://www.fftw.org/), version 3.3 or later 

  - NFFT library (http://www-user.tu-chemnitz.de/~potts/nfft/download.php)
    version 3.2.0 or later

* A C compiler that understands the C99 norm (good recent compilers
  usually do, but I only tested GNU GCC).

Use of GNU make (or of a compatible make utility) will ease the compilation.


2) Compilation

- tar xzvf nfftls-1.0.tgz

- cd nfftls-1.0

- make

3) Use

The program can then be tested on a data file containing 2-column
(time, measurement) ASCII data.  The complete usage message is
obtained with

 nfftls --help

Bernard Leroy
Observatoire de Paris

Bernard DOT Leroy <AT> obspm DOT fr
 
