# Auxiliary files

Additional ASCII text files associated with DEQSOL

Advanced users will need to appreciate the text files that can be used to monitor the course of integration or curve fitting, or to supply data to control simulation and fitting as follows.

w_deqsol.txt
This can be consulted after using DEQSOL to see technical details concerning the integration and optimisation.
It will be found in the ...\simfit\res\ folder.

iterate.txt
This can be consulted after using DEQSOL to see iteration details concerning the integration and optimisation.
It will be found in the ...\simfit\res\ folder.

nagifail.txt
This can be consulted after using the NAG library E04 or D02 routines with DEQSOL to see how to interpret IFAIL values concerning the integration and optimisation.
It will be found in the ...\simfit\bin\ folder.

model files
Run usermod to find out how to supply your own equations.
The examples usermodd.tf1 and deqmod?.tf? should be studied.

configure/initialise files
Most of the details required to configure DEQSOL can be added to model files using the following flags:
begin{limits} ... end{limits}
begin{range} ... end{range}
as will be clear from inspecting the demonstration files deqmod?.tf?.
In addition, configuration can be altered interactively, but it is also possible to input special configuration files.
These set the method, number of parameters and equations, range, number of time points, start values, limits, etc. The examples deqpar?.tf? should be studied.

parameter/limits files
The usual way to set parameter starting estimates and limits for curve fitting is to use the flag
begin{limits} ... end{limits}
on one of the data files supplied for fitting.
In addition, it is possible to use parameter limits files which just contain a list of parameter start estimates and limits.
Deqsol will initialise n parameters if there are n parameter limits in the file supplied, but you will be warned if the model requires fewer than n.
(Important note: here n also includes the y0(i)).
So if j = number of parameters and k = number of y0 (i.e. equations) You would read in n = j + k values to set all parameters, including initial conditions y0(i).

library files
These are the best way to use DEQSOL for curve fitting more than one equation.
Simply use program maklib to make a library file of the data files, but use a percentage sign retrospectively to indicate that data are not available for that component.
You should use the flag
begin{limits} ... end{limits}
on one of the data files.
Note that starting estimates can always be changed interactively, or by reading initialisation or parameter limits files.

Scripts
Some special releases of DEQSOL can be controlled by sripts to make repetitive simulation and/or fitting easier

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