- What is Gepasi?
- Why is Gepasi free, when even academic books are sold?
- Installation / unistallation
- I cannot install Gepasi...
- When I uninstalled Gepasi I was told that not all components had been removed...
- Can I install Gepasi 3 in Windows 3.1x with Win32s?
- User interface
- I have one metabolite that is no longer used in my model. How can I delete it?
- Reloading the current file does not work!
- I read in the help file about a "plot page" but I cannot see it. How do I access this page?
- Simulation engine
- Some models take an excessive long time to execute. What is wrong?
- I want all the data to be output on one single file but the program crashes. What should I do?
- Is there a way of processing a series of simulations without having to manually load and start each one?
1.1 What is Gepasi?
- Gepasi is a Microsoft Windows program intended for the simulation of
the kinetics of systems of chemical and biochemical reactions. The
program is aimed at the study and teaching of the behaviour of such
systems. Gepasi is able to simulate the steady-state and time-course
behaviour of reactions in several compartments of different volumes.
The user supplies the program with information about the
stoichiometric structure of the pathway, kinetics of each reaction,
volumes of the compartments and initial concentration of all chemical
species. The program then builds the differential equations that
govern the behaviour of the system and solves them. Results are
produced in a flexible way so that data can be imported into
spreadsheets or other data processing programs. The data can also be
plotted in 2D and 3D graphs directly from the program (by using the
package gnuplot that is distributed with Gepasi). Gepasi has the
ability of scanning ranges of values of the system parameters and
produce a mapping of the behaviour of the system within these ranges.
Gepasi characterises the steady states that it finds using Metabolic
Control Analysis and linear kinetic stability analysis.
1.2 Why is Gepasi free, when even academic books are sold?
- The comparison is not bad, Gepasi 3.0 has just over 30000 lines of C
and C++ code and the help file contains over 24000 words, totalling
one man year's work. An academic book could be sold for more than
$100, and equivalent commercial software could trade for much more.
However the ideal behind Gepasi is that the average biochemist
should find it easy to model and simulate. Gepasi is being
distributed as free software to help boost the usage of computer
simulation in biochemistry. This product is, nevertheless, fully
protected by international copyright treaties. Further versions of
Gepasi or add-on modules may be distributed as shareware or in some
other commercial format.
2.1 I cannot install Gepasi. When I try to run the program setup.exe an
error message is displayed that says an illegal instruction was
executed and the program closes. What is wrong?
- You have the wrong hardware version of the program. You probably have
an Intel computer and are trying to run the DEC Alpha version (or vice
versa). Make sure you get the right version for your hardware. If you
downloaded Gepasi through the Internet or in a CD-ROM the file
gep30xa.zip is for the Alpha and the file gep30xi.zip is for the Intel.
If you obtained Gepasi in a floppy disk, the label clearly indicates
which version it is.
2.2 I uninstalled Gepasi but at the end a message was printed saying that not all components had been removed. What are these components and what can I do to remove them?
- The uninstall program only removes the files that it installed in the
first place. This message appears when the directory (folder) where
Gepasi was located contains other files (or folders). These other
files are not removed by the uninstall program and therefore the
folder where Gepasi was installed could not be deleted. You can use
file manager or the windows explorer to remove the remaining files and
the folder if you are sure you do not need them.
2.3 Can I install Gepasi 3 in Windows 3.1x with Win32s?
- No.The reason is that Gepasi is multi-threaded and Win32s does not support more than one thread. (By the way the "s" in Win32s stands for "subset.")
3.1 I have defined the reactions of a model but later on I found I had
mistyped one of the reactants. I corrected it but now I have one extra metabolite which I do not want. How can I delete it?
- To get rid of any metabolites that do not participate in any part of
the model call the reactions dialog box and press OK. Gepasi then
deletes metabolites that do not have any involvement in the model,
that is that are not substrates, products or modifiers of any
reaction. If the metabolite you mentioned persists in the model
after calling the reactions dialog then it is because it
participates in reactions (possibly as a modifier).
3.2 Open a gepasi file, change something (say delete some outputs on the task menu), then change your mind and re-open the same file. First, one is not asked whether to save the changed file, and second, nothing actually changes: the new file is not loaded at all.
- This is a well known problem with the Microsoft foundation classes
(MFC) that Gepasi uses. Basically the MFC framework does not load a
file fresh from disk if it is the one being edited at that time. To
get around this do the following:
- do File/New, at this point you are asked if you want to save the changes, reply "no"
- do File/Open and load the file again, you will have the older (unmodified) version of the file
3.3 I read in the help hile about a "plot page" but I cannot see such a
page in Gepasi. How do I access this page?
- You don't see this page because you did not include the "gnuplot"
option when installing the program. You have two options: a) uninstall
and reinstall (be sure to include gnuplot this time) or b) get a copy
of gnuplot, install it on your computer; in Gepasi go to the Options
menu, Add-on modules and type the full path of wgnuplot.exe in the
appropriate box. Both these methods will activate the plot page.
4.1 Some models take an excessive long time to execute while others that
are of similar complexity, run much faster. What is wrong?
- Go to the time course page and make sure that the speed control is
set to "Faster". On some computers even a slight displacement from
the maximum might slow the simulations by a significant amount.
4.2 I want all the data to be output on one single file but the program crashes. What should I do?
- You cannot have time course and steady-state output to a single file. It is impossible.
If you have set both filenames to be equal the simulation engine crashes. To fix this
change the name of one of the files. Version 3.01 does not allow the user to specify
the same file for both tasks.
4.3 Is there a way of processing a series of simulations without having to
manually load and start each one?
- Yes. From version 3.02 onwards there is a command line version of Gepasi
(the file bgepasi.exe) that can do this. This program is only for
processing simulations and so you must have to build and save the *.gps
files with the normal version of Gepasi. As an example, to run the hmm.gps,
chemos1.gps and seqfb.gps files in one go, you would type the following
command in a console (DOS box):
In Windows NT it is easy to schedule batches of simulations to run during
the night by using the AT command:
- bgepasi hmm.gps chemos1.gps seqfb.gps
(You must have administrative previleges to use the WinNT AT command)
- at 23:50 "bgepasi hmm.gps chemos1.gps seqfb.gps"
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