Changes between Version 211 and Version 212 of doc/app/initialization_parameters

Timestamp:

Aug 14, 2013 10:56:34 AM (11 years ago)

Author:

raasch

Comment:

--

doc/app/initialization_parameters

@@ -724 +724 @@
 FFT-method to be used.\\\\
 The fast fourier transformation (FFT) is used for solving the perturbation pressure equation with a direct method (see [#psolver psolver]) and for calculating power spectra (see [../packages optional software packages]).\\\\
-By default, system-specific, optimized routines from external vendor libraries are used. However, these are available only on certain computers and there are more or less severe restrictions concerning the number of gridpoints to be used with them.\\\\
+By default, system-specific, optimized routines from external vendor libraries are used. However, these are available only on certain computers and there are sometimes more or less severe restrictions concerning the number of gridpoints to be used with them.\\\\
 There are two other PALM internal methods available on every machine (their respective source code is part of the PALM source code):\\\\
 1.:  The '''Temperton'''-method from Clive Temperton (ECMWF) which is computationally very fast and switched on with '''fft_method''' = '' 'temperton-algorithm'.'' The number of horizontal gridpoints ([#nx nx]+1, [#ny ny]+1) to be used with this method must be composed of prime factors 2, 3 and 5.\\\\
-2.:  The '''Singleton'''-method which is very slow but has no restrictions concerning the number of gridpoints to be used with, switched on with '''fft_method''' = '' 'singleton-algorithm'.'' 
+2.:  The '''Singleton'''-method which is very slow but has no restrictions concerning the number of gridpoints to be used with, switched on with '''fft_method''' = '' 'singleton-algorithm'.''\\\\
+Furthermore, the fftw (see http://www.fftw.org ) can be used by setting '''fft_method''' = '' 'fftw' ''. This also requires to set the cpp-preprocessor switch {{{-D__fftw}}} in the {{{%cpp_options}}}-line of the configuration file, and to give the paths to the respective fftw include file and library by a {{{%fftw_inc}}} and {{{%fftw_lib}}} line, respectively. 
 }}}
 |----------------