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File formats

 

Introduction

This section describes the file formats for the different kinds of data files that can be read or saved using xrk. Most users will not need this information right away, but it is useful in the following situations.

The table below summarizes the four different classes of data files associated with xrk. Specifically, the last column in the table shows what values are contained in each file.

tabular571

The tutorial contains examples of reading and saving these data files.

Conventions used

Before describing each of the file formats in detail, we introduce some helpful notation.

tabular580

Note that the convention is for subscripts to start at 0 rather than 1. This is to keep the notation in this section consistent with that in the program.

Parameter files

These files contain the npar values of the model parameters and have the extension .par by default. The file format is as follows. The first line contains the value of npar. The second line contains the value of tex2html_wrap_inline1417 . The next line contains the value of tex2html_wrap_inline1419 , and so on, up to tex2html_wrap_inline1421 , as shown below.

displaymath1411

If npar doesn't match the number of parameters in the current model, a warning dialog appears and the parameter values are not changed. The program also checks to make sure that the correct number of values are read from the file. If this doesn't happen, a warning dialog appears and the parameter values are not changed.

Complete set

As the name implies, these files contain a complete set of parameter values and initial conditions. By default, these files have the extension .set. The file format is that obtained by adding the initial conditions to a parameter file, as shown schematically below.

displaymath1425

The program checks that npar and N match the current model. It also checks that the correct number of parameter values and intial conditions are read in. If any of these checks fail, a warning dialog appears and the parameter values and initial conditions are not changed.

Snapshot files

Snapshot files contain a sequence of tex2html_wrap_inline1433 values at equally spaced time intervals. These files are output only and cannot be read into xrk. They are intended for use with a separate plotting program to produce two-dimensional plots of tex2html_wrap_inline1435 . Suppose that there are L+1 equally spaced values of time, tex2html_wrap_inline1439 , k=0, L. Then a snapshot file consists of L+1 lines of values of tex2html_wrap_inline1445 separated by blank lines. For the sake of convenience, each line also contains the time value tex2html_wrap_inline1439 . The file format is shown schematically below,

displaymath1431

By convention, tex2html_wrap_inline1449 .


next up previous
Next: Maple programs for plotting Previous: Program appearance and Controls

William W. Farr
Fri Oct 25 13:53:45 EDT 1996