As described in the section Overview: MPS-Format SAS Data Set, the MPS or QPS format is a standard file format for describing linear, integer, and quadratic programming problems. The MPS/QPS format is defined for plain text files, whereas in the SAS System it is more convenient to read data from SAS data sets. Therefore, a facility is required to convert MPS/QPS-format text files to MPS-format SAS data sets. The SAS macro %MPS2SASD serves this purpose.
In the MPS/QPS-format text file, a record refers to a single line of text that is divided into six fields. MPS/QPS files can be read and printed in both fixed and free format. In fixed MPS/QPS format, each field of a data record must occur in specific columns:
|
Field |
Field 1 |
Field 2 |
Field 3 |
Field 4 |
Field 5 |
Field 6 |
|
Columns |
2–3 |
5–12 |
15–22 |
25–36 |
40–47 |
50–61 |
In free format, fields of a record are separated by a space. Both fixed and free format have limitations. If users need to use row names or column names longer than 8 characters, then there is not enough space to hold them in fixed format. If users use a space as a part of a row name or column name, such as "ROW NAME", then free-format MPS format interprets this symbol as two fields, "ROW" and "NAME".
You can insert a comment record, denoted by an asterisk (*) in column 1, anywhere in an MPS/QPS file. Also, if a dollar sign ($) is the first character in field 3 or field 5 of any record, the information from that point to the end of the record is treated as a comment. All comments are ignored by the %MPS2SASD macro, described as follows.
%MPS2SASD (MPSFILE='infilename', OUTDATA=mpsdata, MAXLEN=n, FORMAT=FIXED/FREE);