libRootFftwWrapper -- A ROOT wrapper for FFTW3 Ryan Nichol ([email protected]) -- December 2007 ###############################################################################
This is a simple wrapper library that provides an interface to FFTW for use with ROOT.
ROOT (http://root.cern.ch) FFTW3 (http://www.fftw.org/)
i) Ensure both ROOT and FFTW3 are on your system and that ROOTSYS is correctly set (or root-config is in your path) and that the directory containing libfftw3 is in either the system or your own LD_LIBRARY_PATH. ii) Make sure that cmake is installed on your system iii) Set the environmental variable ANITA_UTIL_INSTALL_DIR to point to your desired installation dir (libraries will be installed in a lib subdirectory from this location) iii) To build the code:
Right now, we recommend you build using cmake:
(optional) make configure make make install
To use the old build system:
(optional) modify Makefile.config to suit your needs
make legacy
make legacy-install
Trying to mix the two build systems might get things confused
For Mac OS X I would recommned usinge homebrew to install FFTW, ROOT and cmake. See http://brew.sh After installing brew you can get all the prerequisites by doing brew update brew install cmake brew install fftw brew tap homebrew/science brew install root6
a) Ensure that the directory containing the libRootFftwWrapper library is in your LD_LIBRARY_PATH (e.g. ANITA_UTIL_INSTALL_DIR/lib ) b) To load the library you can (note the lack of .so or .dylib): gSystem->Load("libRootFftwWrapper"); c) The FFTWComplex and FFTtools classes should now be accessible from the ROOT prompt or ROOT macro.
Most of the member functions have fairly descriptive names, the documentation is at present somewhat lacking.
At some point, FFTtools changed from a static-method-only class to a namespace so that other things could be added to the FFTtools namespace. This was thought not to adversely affect anyone, since the FFTtools::doFFT, etc. usage would remain the same. However, apparently some users had code which did things like: FFTtools tools; tools.doFFT( );. Even though the instance is extraneous, it may be a pain to go through a lot of legacy code to fix it. For this reason, a libRootFftwWrapperCompat shared library is also created, which should be compatible with old uses of the library. To compile old code against it, you will need to define FFTTOOLS_COMPAT_MODE somehow, either like:
#define FFTTOOLS_COMPAT_MODE #include "FFTtools.h"
or by adding -DFFTTOOLS_COMPAT_MODE to your compilation flags (either with CXX_FLAGS or in the build system)