> > ILOG CPLEX File Formats > VEC File Format

This file format is available if you use the ILOG CPLEX barrier optimizer. In a VEC file, spaces differentiate entries on a line. Blank spaces are not allowed within names or values. Blank lines are not permitted.

ILOG CPLEX reads and writes VEC files in a standard format consisting of a NAME line, VARIABLE lines, CONSTRAINT lines, and an END line.

NAME line, a single line, the first in the file, defines the name of the problem. For example,

NAME          problem-name

VARIABLE lines, a separate one for each variable, consist of four fields, like this:

c  cname  primal-value   reduced-cost

Table 7 Fields in a VARIABLE line of a VEC file

Field 
Purpose 
c 
letter c indicates a column 
cname 
name of the variable 
primal-value 
value of the primal variable in that column 
reduced-cost 
reduced cost of that variable 

CONSTRAINT lines, a separate one for each constraint, also consist of four fields, like this:

r  rname  slack-value    dual-value

Table 8 Fields in a CONSTRAINT line of a VEC file

Field 
Purpose 
r 
letter r indicates a row 
rname 
name of the constraint 
slack-value 
value of the slack (artificial) variable on that row 
dual-value 
dual variable on that row 

END line, consisting of the token ENDATA, completes a VEC file.