The MOSEK Python optimizer API manual Version 7.0 (Revision 141)

616 APPENDIX F. MOSEK FILE FORMATS
* 1 2 3 4 5 6
*23456789012345678901234567890123456789012345678901234567890
NAME
[name]
?? [vname1] [value1]
ENDATA
Figure F.1: The standard ORD format.
The format is based on the TAR (USTar) file format. This means that the individual pieces of data
in a .task file can be examined by unpacking it as a TAR file. Please note that the inverse may not
work: Creating a file using TAR will most probably not create a valid MOSEK Task file since the
order of the entries is important.
F.5 The XML (OSiL) format
MOSEK can write data in the standard OSiL xml format. For a definition of the OSiL format please
see http://www.optimizationservices.org/. Only linear constraints (possibly with integer variables) are
supported. By default output files with the extension .xml are written in the OSiL format.
The parameter iparam.write xml mode controls if the linear coefficients in the A matrix are written
in row or column order.
F.6 The ORD file format
An ORD formatted file specifies in which order the mixed integer optimizer branches on variables. The
format of an ORD file is shown in Figure F.1. In the figure names in capitals are keywords of the ORD
format, whereas names in brackets are custom names or values. The ?? is an optional key specifying
the preferred branching direction. The possible keys are DN and UP which indicate that down or up
is the preferred branching direction respectively. The branching direction key is optional and is left
blank the mixed integer optimizer will decide whether to branch up or down.
F.6.1
An example
A concrete example of a ORD file is presented below:
NAME
EXAMPLE
DN x1 2
UP x2 1
x3 10
ENDATA
This implies that the priorities 2, 1, and 10 are assigned to variable x1, x2, and x3 respectively. The
higher the priority value assigned to a variable the earlier the mixed integer optimizer will branch on
that variable. The key DN implies that the mixed integer optimizer first will branch down on variable
whereas the key UP implies that the mixed integer optimizer will first branch up on a variable.
If no branch direction is specified for a variable then the mixed integer optimizer will automatically