System requirements and instructions for installing PRECIS.
Linux
PRECIS runs only under GNU/Linux on a PC.
OpenSUSE Linux is our recommended distribution.
Look on the Internet for tutorials. A good basic one can be found at
http://lowfatlinux.comMachine RequirementsChoose the fastest system possible, with an Intel or AMD multi-core CPU (the more cores the better).
The default installation of PRECIS is not designed to run on distributed memory clusters systems (i.e. cluster or supercomputer systems in which dedicated job control / scheduling / queuing software is present). PRECIS can be made to work on such systems at additional cost (email for details).
At least 512MB memory (1 GB per CPU core is preferred)
Lots of disk space (>500GB)
UPS (if required)
General Install RequirementsFor a system whose main purpose is to run PRECIS, it is recommended to use a a standard 64 bit Linux installation.
Required packages: - Mozilla or Mozilla Firefox
- atd (the AT daemon)
- pdksh (public domain Korn Shell) or ksh (korn shell)
- gnuplot (for plotting in pp data, an analysis tool).
- gv (GhostView, for viewing *.ps postscript files)
- Imagemagick
- gawk (Gnu awk)
- a PDF file viewer such as Acrobat Reader or kpdf
- a text editor program like Emacs or Pico are helpful
- Set up a 'precis' user account during the installation
Disk LayoutDecide on the disk layout.
The default is OK for single disk system. For dual disk systems, bear in mind the larger directories:
Input data 100GB-500GB (i.e. $PP4LBCDIR)
Work data 10GB (i.e. $DATADIR)
Output data 100GB-1TB depending on output diagnostic options (i.e. $ARCHIVEDIR)
As an example, if you have a 100GB drive and 500GB drive installed in your PC, when installing PRECIS choose the location of the 500GB drive for the larger directories.
Main Installation points
Description of directories:System directories UMDIR
/home/precis/um The PRECIS system code. All of the required files are copied to this directory at the end of the installation process.
MY_OUTPUT
/home/precis/precis_out Output directory for PRECIS run time messages
Work directories DATADIR
/home/precis/precis_expt Directory used by PRECIS when it is running to store control and intermediate files. This includes the current output data files and log files. A directory named $DATADIR/RUNID, where RUNID is the five letter internal PRECIS run ID of the experiment, will be created when PRECIS is run.
ANCILDIR
/home/precis/ancil Directory where the processed ancillaries for the selected region are stored. For a given RUNID the ancillaries will be located in $ANCILDIR/RUNID
LBCDIR
/home/precis/lbc Directory where the processed input LBCs are stored. For a given RUNID the LBCs will be located in $LBCDIR/RUNID
Input data directories ANCIL_MASTER
/home/precis/ancil/master The global master ancillary files. All of the required files are copied at the end of the installation process.
PP4LBCDIR
/home/precis/pp4lbc The files required to generate the LBCs used by PRECIS. These files have to be obtained from the Met Office. The files required to generate the LBCs for each driving experiment should be placed in their own subdirectory, i.e. the LBCs for GCM with ID addfa should be copied to $PP4LBCDIR/addfa
DUMPSDIR
/home/precis/dumps Location of the initial PRECIS dumps. These files have to be obtained from the Met Office. All initial dumps should be copied to this directory. Do not use subdirectories.
Output directory ARCHIVEDIR
/home/precis/archive Directory into which the output diagnostic files are copied. For a given RUNID the output files will be copied to $ARCHIVEDIR/RUNID
Temporary directory TMPDIR
/home/precis/precis_expt/tmp Directory where the temporary files generated when PRECIS is run are located.
How to InstallPlease find instructions on how to install PRECIS
here.
After the ./install_precis script is complete,
Source setvars
Code:
. ~/setvars
Start PRECIS
Code:
precis
Run an experiment!
Extra ContentsIn ~/utils of the download there are several install packages:
- pdksh - the korn shell (required)
- xanim (required for animations)
- gnuplot
- ghui/umui for previous users of the Portable UM
- The statistical package R and Rclimdex
- pp2netcdf -- convert from PP format to NetCDF format
- NCL (NCAR Command Language - for NetCDF)