When you run ./configure on a supported system you will be prompted to enter compiler optimisation flags. We have not attempted to provide the best optimisation flags for all operating systems. The configure script will have a guess at optimisation options for some systems, but it is up to the user to figure out an optimal set1 From our experience, we have not found significant accumulation of numerical error even when using the most aggressive optimisation level available.
A feature introduced in the previous release and enhanced in the current one, is that the configure script creates a shell profile according to shell type in which various environment variables and aliases are defined for your convenience. If you agree upon prompting, it will also change your default system profile during installation to automatically source this profile. If you do not agree to this change, you will need to explicitly source the profile for any session in which you intend to run HEALPix facilities. In particular, you will have to make sure that the HEALPIX system variable is correctly defined (as the full path to the HEALPix directory) before running the package.
And finally, the current ./configure script allows several compilations of the Healpix routines to coexist by letting the user choose the name of directories containing the executables, libraries and include files.
A typical configuration session for a user running on a PC running under Linux, with the Intel Fortran Compiler (version 8.1 or 9.0), is as follows:
%./configure you seem to be running Linux enter name of your F90 compiler (): ifort Note: your Fortran compiler is Intel Fortran Compiler compiled Healpix products will be: BINDIR = ./bin[suffix] INCDIR = ./include[suffix] LIBDIR = ./lib[suffix] and the Makefile will be copied into Makefile[suffix] enter suffix for directories (): _ifort compiled Healpix products will be: BINDIR = ./bin_ifort INCDIR = ./include_ifort LIBDIR = ./lib_ifort Warning: The following directories could not be found: ./bin_ifort ./include_ifort ./lib_ifort Should I attempt to create these directories (Y|n)? enter compilation flags for ifort compiler (-I$(INCDIR) -Vaxlib -cm -w -vec_report0): enter optimisation flags for ifort compiler (-O3): Fortran code will be compiled with ifort -O3 -I$(INCDIR) -Vaxlib -cm -w -vec_report0 enter name of your C compiler (cc): enter compilation/optimisation flags for C compiler (-O): C subroutines will be compiled with cc -O enter command for library archiving (ar rv): enter full name of cfitsio library (libcfitsio.a): enter location of cfitsio library (/usr/local/lib): The Spherical Harmonics Transform routines used by synfast/anafast/smoothing/plmgen and some routines used by ud_grade and alteralm respectively have a parallel implementation (based on OpenMP). It has currently been tested on IBM/xlf and Linux/ifc systems/compilers Do you want to use : 0) the standard scalar implementation ? 1) the parallel implementation (slightly slower in single CPU usage with some compilers) Enter choice (0): The following line should be inserted into your shell profile (/home/user/.cshrc): source /home/user/Healpix_2.00/bin_ifort/profile.HEALPix profile.HEALPix contains the following commands: # tcsh configuration for HEALPix setenv HEALPIX /home/user/Healpix_2.00 setenv HEXE /home/user/Healpix_2.00/bin_ifort setenv PATH ${PATH}:${HEXE} alias hidl "idl /home/user/Healpix_2.00/src/idl/HEALPix_startup" alias hidlde "idlde /home/user/Healpix_2.00/src/idl/HEALPix_startup" Do you want this modification to be done (y|N)? Configuration finished. Now run "(GNU)make" to build the package, and "(GNU)make test" to test it. You can configure the IDL previewer by running ./config_preview
Eric Hivon 2005-08-31