[Clp] initialBarrierSolve aborts program on infeasible problem

Henning Thielemann coinor at henning-thielemann.de
Wed Dec 6 06:38:46 EST 2023


Attached is a C++ program that loads the according MPS file. All methods 
other than initialBarrierSolve correctly report the infeasibility via 
status, but initialBarrierSolve aborts the program:

$ ./dual-off-infinity
Coin0001I At line 1 NAME          ClpDefau
Coin0001I At line 2 ROWS
Coin0001I At line 11 COLUMNS
Coin0001I At line 21 RHS
Coin0001I At line 29 RANGES
Coin0001I At line 32 BOUNDS
Coin0001I At line 37 ENDATA
Coin0002I Problem ClpDefau has 7 rows, 2 columns and 7 elements
Clp0027I Model was imported from dual-off-infinity.mps in 0.005772 seconds
Coin0507I Presolve determined that the problem was infeasible with 
tolerance of 1e-08
Clp3003W Analysis indicates model infeasible or unbounded
10 elements in sparse Cholesky, flop count 50
Clp0035I 0 Primal 59.5 Dual -7380.5 Complementarity 10400 - 0 fixed, rank 
7
Clp0035I 1 Primal 37.269361 Dual -4818.557 Complementarity 8228.2218 - 0 
fixed, rank 7
Clp0035I 2 Primal 5.3815103 Dual -1210.1408 Complementarity 6488.4133 - 0 
fixed, rank 7
Clp0035I 3 Primal 5.3670364 Dual -387.33899 Complementarity 6191.7066 - 0 
fixed, rank 7
Clp0035I 4 Primal -308.02974 Dual -1659.0514 Complementarity 1955.8582 - 0 
fixed, rank 7
Clp0035I 5 Primal -310.02859 Dual -456.46006 Complementarity 891.5754 - 0 
fixed, rank 7
Clp0035I 6 Primal -561.18452 Dual -386.5366 Complementarity 664.66908 - 0 
fixed, rank 7
Clp0035I 7 Primal -560.11826 Dual -362.00813 Complementarity 657.36761 - 0 
fixed, rank 7
Clp0035I 8 Primal -549.72977 Dual 6668.613 Complementarity 275.30541 - 0 
fixed, rank 7
Clp0035I 9 Primal -549.72132 Dual 324122.17 Complementarity 150.01422 - 0 
fixed, rank 7
Clp0035I 10 Primal -549.72132 Dual 324122.73 Complementarity 149.46374 - 0 
fixed, rank 7
Clp0035I 11 Primal -549.72132 Dual 324122.74 Complementarity 149.45825 - 0 
fixed, rank 7
Clp0035I 12 Primal -549.72138 Dual 324122.74 Complementarity 144.37258 - 0 
fixed, rank 7
Clp0035I 13 Primal -549.72138 Dual 324123.04 Complementarity 144.08214 - 0 
fixed, rank 7
Clp0035I 14 Primal -549.72138 Dual 324123.04 Complementarity 144.07924 - 0 
fixed, rank 7
Clp0035I 15 Primal -549.72138 Dual 324123.04 Complementarity 144.07921 - 0 
fixed, rank 7
Clp0035I 16 Primal -549.72138 Dual 1.4841976e+41 Complementarity 135.52492 
- 0 fixed, rank 7
Clp0035I 17 Primal -549.72138 Dual -1.852911e+88 Complementarity 
1.852911e+88 - 0 fixed, rank 7
dual off to infinity
Aborted


You can see that {cout << "status: "} is not reached.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dual-off-infinity.cpp
Type: text/x-c++src
Size: 318 bytes
Desc: 
URL: <http://list.coin-or.org/pipermail/clp/attachments/20231206/93f2c9c7/attachment.bin>
-------------- next part --------------
NAME          ClpDefau
ROWS
 N  OBJROW
 L  R0000000
 L  R0000001
 G  R0000002
 L  R0000003
 L  R0000004
 L  R0000005
 L  R0000006
COLUMNS
    C0000000  OBJROW     -7.        
    C0000000  R0000000  5.          
    C0000000  R0000001  1.          
    C0000000  R0000002  8.          
    C0000000  R0000004  2.          
    C0000000  R0000006  4.          
    C0000001  OBJROW    7.          
    C0000001  R0000000  9.          
    C0000001  R0000002   -2.        
RHS
    RHS       R0000000  20.         
    RHS       R0000001  94.         
    RHS       R0000002  8.          
    RHS       R0000003  65.         
    RHS       R0000004  45.         
    RHS       R0000005  95.         
    RHS       R0000006   -40.       
RANGES
    RANGE     R0000004  61.         
    RANGE     R0000005  48.         
BOUNDS
 LO BOUND     C0000000   -104.      
 UP BOUND     C0000000  63.         
 LO BOUND     C0000001   -89.       
 UP BOUND     C0000001  65.         
ENDATA


More information about the Clp mailing list