FIT2D is available free of charge
in return of an undertaking for appropriate acknowledgement of use of
the program and the methods. Use of FIT2D for commercial purposes
is not allowed.
The "Conditions of Use" are intended to allow freedom of use for personal
academic research provided suitable acknowledgement of the program and
methods is given.
Previously, a "software key" was used to control use of the program to
registered users, this has now been removed from all versions. This means that
users can use the program immediately, and can change computer systems
without needing new keys, but has the disadvantage that there is now no
record of who is using the program.
The FIT2D home page is at URL:
http://www.esrf.fr/computing/scientific/FIT2D.
Here there are links to obtain documentation and the available
executable files.
To obtain executable files, PostScript documentation, and a "Conditions
of Use" form use the following (or similar):
(This will list the files in the directory.)
(Here you will be prompted for the different files starting with "fit2d"
enter "y" for the required executable.)
(Here you will be prompted for the different files starting with "fit2d"
enter "y" for the required PostScript file (.ps).)
(To end the ftp session.)
Having transferred the executable file by ftp you will probably want to
change the file-name and have to change the file permission to make it
"executable". e.g.
Now you should be able to run FIT2D:
This should open a window for graphics output, and produce "banner"
text and other text in the terminal window. Without the "software
key" the program will not enter the main menu.
Registering as a FIT2D User
Using a Web Browser to Obtain FIT2D
Obtaining FIT2D by aftp
FIT2D executables for various machine and operating
system types can be
obtained by anonymous ftp from www.esrf.fr (COMPAQ-ALPHA TRU64 V4,
HP-800 HP-UX V10, IBM RS6000 AIX 4, Silicon Graphics Irix 6.5,
PC Linux, SunOS V5
(Solaris), and Windows (95/98/ME/NT/2000 versions are presently available.)
> ftp www.esrf.fr
user name> anonymous
enter user name and machine as password>
> cd pub
> cd expg
> cd FIT2D
> ls
> bin
> mget fit2d*
> ascii
> mget fit2d
> quit
> mv fit2d_10.30_alpha_OSFV4.0 fit2d
> chmod +x fit2d
> fit2d
FIT2D uses allocation of virtual memory at run
time to allow almost unlimited
flexibility in the size of images which may be processed. The limits are
generally set by the limitations of the underlying computer system and not
by FIT2D. Within very flexible limits the user
defines the sizes of work
arrays at the start-up of FIT2D. Since some images may
be very large it is
useful to understand the storage needs.
Normally FIT2D stores 2 arrays: the current data array
and the "memory".
Each uses 4-byte reals as the storage element per pixel. Additionally the
"FIT" sub-menu creates a "masking" array which is 1-byte per pixel. This
is used for fitting operations and for powder diffraction re-binning. Thus
in general 9-bytes per pixel may be used. The program uses a small number of
other arrays, also allocated dynamically e.g. for image display. So typically
5 Mbytes are needed for FIT2D even with very small data
arrays. An
approximate formula for the total memory requirement is:
Required memory = 9 * X_DIMENSION * Y_DIMENSION + 5 Mbytes
e.g. If X_DIMENSION = Y_DIMENSION = 1024, about 14 Mbytes total memory is
required.
If X_DIMENSION = 2048, Y_DIMENSION = 4096, about 77 Mbytes is needed.
This total memory can be virtual memory and does not need to be RAM, but it
is clearly advisable to be able to able to store at least one complete
data-set in RAM.
If this causes problems it is possible to work with only the current data
array i.e. only 4-bytes per pixel, and it is possible to work with only a
sub-region of the data, or with the data rebinned into a smaller array.
For the second example it should be recommended to have 96 Mbyte of
RAM (some extra memory for other users), and about 80 Mbyte of swap space
per FIT2D process or similar analysis program.
So perhaps 200-300 Mbytes of
swap should be permanently established in a "swap file". (Using temporarily
allocated swap space will cause problems as the temporary disk space gets
filled up. One day a previously running program will no longer run !
Disk space is so cheap these days it's foolish to try to economise on swap
space.)
It is almost impossible to define time limits, owing to the flexible and
interactive nature of FIT2D. Probably most users will
use FIT2D for about
0.5 hours, but some will use it for much shorter or much longer periods.
"Batch" style processing is possible which could involve longer periods.
This page has been produced by Andy Hammersley
(E-mail: hammersley@esrf.fr).
It is subject to further modification. If you have helpful suggestions,
please send them to me.
APPENDIX A: System Requirements
Memory Requirements
Time Requirements