In addition to the matrix files described above certain options within MX may make use of external input data and/or control files, e.g. to define the row and/or column totals to Furness a trip matrix. While this data may be defined interactively it is very often easier for the user to prepare large data sets “off line” with an editing program. External data sets once created may be used for repeated operations of the same program.
In a slightly different sense the MX preferences file, MX0.DAT, may also be viewed as a control file. A new version may be created from within the Files Menu.
Figure 10.2 - MX File Structure
Note that a single run of the program may use more than one input control file - each file is “opened” and “closed” as and when needed by the program. Equally the input .UFM files are not fixed and may be redefined during a run and more than one output file may be created (but at any one time only one exists).