Initializing help system before first use

XPRSreadbasis (READBASIS)

Purpose
Instructs the Optimizer to read in a previously saved basis from a file.
Topic areas
File IO, LP
Synopsis
int XPRS_CC XPRSreadbasis(XPRSprob prob, const char *filename, const char *flags);
READBASIS [-flags] [filename]
Arguments
prob 
The current problem.
filename 
A string of up to MAXPROBNAMELENGTH characters containing the file name from which the basis is to be read. If omitted, the default problem_name is used with a .bss extension.
flags 
Flags to pass to XPRSreadbasis ( READBASIS):
n 
input basis file containing basic solution values;
t 
input a compact advanced form of the basis;
v 
use the provided filename verbatim, without appending the .bss extension;
z 
read a compressed input file.
Example 1 (Library)
If an advanced basis is available for the current problem the Optimizer input might be: 
XPRSreadprob(prob,"filename","");
XPRSreadbasis(prob,"","");
XPRSmipoptimize(prob,"");
This reads in a matrix file, inputs an advanced starting basis and maximizes the MIP.
See also example addmipsol.c.
Example 2 (Console)
An equivalent set of commands for the Console user may look like: 
READPROB
READBASIS
MIPOPTIMIZE
Further information
1. The only check done when reading compact basis is that the number of rows and columns in the basis agrees with the current number of rows and columns.
2. XPRSreadbasis ( READBASIS) will read the basis for the original problem even if the matrix has been presolved. The Optimizer will read the basis, checking that it is valid, and will display error messages if it detects inconsistencies.
3. This function cannot be called while the current problem is being solved or when it is in an interrupted state. Use XPRSpostsolve to restore the problem to a non-solving state.
Related topics
XPRSloadbasis, XPRSwritebasis ( WRITEBASIS).

Parent Topic Console and Library Functions

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