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IBM Corp. 1995, 1997. All rights reserved.
Purpose: To solve LP problems Interior-Point Barrier methods
Usage: oslbslv ["?"] [-keyword=value] [...] [@keyword_file]
keyword_file: Name of file containing "-keyword=value" strings.
Each "-keyword=value" string in this file must be on a separate line.
Valid Keywords and Default Values:
Maxmin = min|max - default: min
input = input_mps_file - default: standard input
output = listing_file - default: standard output
dspace = value - default: 400000
isolmask = value - default: 0
iprtinfomask = value - default: 31
presolve = yes|no - default: yes
presolvetype = 0|1|2|3 - default: 3
scale = yes|no - default: yes
outbasis = out_basis_file - default: null
imaxiter = value - default: 9999999
imaxiterb = value - default: 100
alg = 0|1|2|3 - default: 0
sslvswch = 0|1|2|3 - default: 2
osli_n_= value - default: a function of n
oslr_n_= value - default: a function of n
oslc_n_= value - default: a function of n
Explanation of Keywords:
maxmin : Solve as a maximization or minimization problem.
input : Name of file containing input data - MPS format.
output : Name of file to receive output messages.
dspace : Size in double words of work area.
isolmask : Matrix bit mask for EKKPRTS print function.
= 1 : selects the rows
= 2 : selects the columns
= 4 : selects the nonzero elements of the model
= 8 : selects the infeasible elements of the model
= 15 or 0 or 16 : selects the entire matrix
iprtinfomask : Solution information bit mask for EKKPRTS print function.
= 1 : selects the statistics
= 2 : selects iteration count, value of the objective function and the problem status
= 4 : selects the names of the columns and rows
= 8 : selects the status of each variable
= 16 : selects the row and column solution values
= 32 : selects the dual values and reduced costs
= 64 : selects the lower bounds
= 128 : selects the upper bounds
= 256 : selects the input costs
= 512 : selects the matrix elements
= 0 : selects all of first six options (same as 63).
presolve : Use EKKPRSL function to pre-solve problem.
presolvetype : Type of reduction to be performed by EKKPRSL.
= 0 : the redundant rows are eliminated, the variables summing to zero are fixed.
= 1 : type 0 reductions are done and the doubleton rows are eliminated.
= 2 : type 0 reductions are done and variable substitutions performed.
= 3 : all of type 0, 1, and 2 reductions are performed.
scale : Use EKKSCAL function to scale the coefficient matrix.
outbasis : Name of file containing an output basis created by EKKBASO.
imaxiter : The max. number of Simplex iterations that will perform done.
imaxiterb : The max. number of Barrier iterations that will perform done.
alg : Interior-Point Barrier alg. to be used by EKKBSLV function.
= 0 : algorithm to be chosen by the solver
= 1 : primal barrier algorithm
= 2 : primal-dual barrier algorithm
= 3 : primal-dual barrier alg. with predictor-corrector
sslvswch : Simplex method switch (to obtain a basic solution).
= 0 : EKKBSLV never switch to the simplex method
= 1 : EKKBSLV switches to the simplex method if numerical instabilities arise
= 2 : EKKBSLV switches to the simplex method when it completes or if numerical instabilities arise
= 3 : EKKBSLV switches to the simplex method immediately if it is appropriate after analyzing the matrix, at completion, or if numerical instabilities arise
osli_n_ : Integer Control variable n; 0 < n < 62
oslr_n_ : Real Control variable n; 0 < n < 46
oslc_n_ : Character Control variable n; 0 < n < 11
See the library User's Guide for more information on Control variables.
Example 1
oslbslv "?"
This command results in the usage information and display of valid keywords, their meanings along with the default values.
Example 2
oslbslv -imaxiterb=70 < test1.mps > test1.out
The oslbslv program is started using test1.mps as input data. Output is directed to the file test1.out. The program will switch to a Simplex method after 70 Interior-Point Barrier iterations.
Example 3
If the file key_file.001 contains the following 4 lines:
presolve=no
alg=1
imaxiterb=70
osli_36_=132
then the command:
oslbslv -dspace=1000000 @key_file.001 < test1.mps > test1.out
will start oslbslv with a work area of 1 million double words. The ekkprsl() pre-solve function will not be invoked. The Primal-Barrier algorithm will be used. The program will switch to a Simplex method after 70 Interior-Point Barrier iterations. The maximum number of characters on each line of output is 132.
Example 4
The command:
oslbslv -dspace=1000000 @key_file.001 -input=test1.mps -output=test1.out
is equivalent to:
oslbslv -dspace=1000000 @key_file.001 < test1.mps > test1.out
oslbslv USAGE NOTES
1. If oslbslv is having difficulty with a problem, then you should increase the size of work area using the "dspace" keyword and try solving the problem again.
System Requirements
The installation instructions in the download package include System Requirements