Frequently Asked Questions

1) dyn.Opt does not start, I get an error message like: Can't find class "xyzzy".
2) What are the files with names like "D****T.java" and "D****T***.class"?
3) How do I plot the results?
4) Where and how are the results stored?
5) How do I enter an initial guess for the optimal trajectory?
6) The cut and paste commands do not work.
7) No text appears in the dyn.Opt GUI.
8) What does the "java.lang.OutOfMemoryError" message mean?

A:    Please read the Installation section of the User's Guide, most likely the CLASSPATH variable has not been set correctly.
 

2) What are the files with names like "D****T.java" and "D****T***.class"?

A:    These are temporary files created by the dyn.Opt application.  These files are the Java code generated from the user input.  The files are deleted on completion of the problem execution.
 

3) How do I plot the results?

A:    Please see the Plot Menu section of the User's Guide.
 

4) Where and how are the results stored?

A:     The results from the problem execution are stored in the file "filename.stcl".  This file contains the state and control variables at each time node.  See the output_file keyword in the Problem Entry section of the User's Guide for a description of the format of this file.  If the problem contains parameters the file "filename.parm" contains the results for these variables.  In both cases filename can be specified using the keyword output_file = filename in the problem entry.  If no output_file is specified the current file name is used.
 

5) How do I enter an initial guess for the optimal trajectory?

A:     An initial guess for the state, control and parameters can be entered via a data input file.  See the input_file keyword in the Problem Entry section of the User's Guide for a description of the format of this file.  Note that if the problem contains parameters both a .stcl file and a .parm file are required.
 

6) The cut and paste commands do not work.

A:    Some of the java.awt.TextArea methods in jdk1.1.1 for Windows95 do not work as advertised, as a result edit commands  sometimes give unexpected results.
 

7) No text appears in the dyn.Opt GUI.

A:  No text appears in the edit area when a file is opened.  This problem occurs with jdk1.1.5v5-980311 for Linux.  To make the text visible resize the dyn.Opt window manually.

8)  What does the "java.lang.OutOfMemoryError" message mean?

A:   You need to increase the heap size for the Java interpreter.  Try,

                java -ms16m -mx32m dyn.Opt

This will make the initial heap size 16M (default 1M) and the maximum heap size 32M (default 16M).