Since it is expected that SATURN matrices will include a large number of different “types” of matrices, e.g., trip matrices, distance matrices, cost matrices, it is very useful for the user to define the sort of elements held in the matrix file. For example it makes the output much more legible when totals from a trip matrix are clearly marked “trips”, costs are shown as being in pounds, etc. etc. This is done within SATURN by defining a series of “parameters” which specify the elements stored on each matrix file.
Thus we store information on:
♦ the “dimensions” of the elements, e.g., whether they are times, distances, costs, etc.;
♦ their “units”, e.g., minutes, miles, pounds, etc.
These are either defined on the input data files (10.5.1) as up to 8 characters or may be interactively defined within MX (under Matrix Manipulation 10.8 or UFM Output 10.16.7).