clpAPI-package: R Interface to C API of COIN-OR Clp

In clpAPI: R Interface to C API of COIN-or Clp

Description

A low level interface to COIN-OR Clp (COIN Linear Program code).

Details

The package clpAPI provides access to the callable library of COIN-OR Clp from within R.

Author(s)

Gabriel Gelius-Dietrich <[e-mail]>

Maintainer: Mayo Roettger <[e-mail]>

References

The COIN-OR Clp home page at https://projects.coin-or.org/Clp

Examples

# load package
library(clpAPI)

# preparing the model
lp <- initProbCLP()

nrows  <- 5
ncols  <- 8

# objective function
obj    <- c(1, 0, 0, 0, 2, 0, 0, -1)

# upper and lower bounds of the rows
rlower <- c(2.5, -1000, 4, 1.8, 3)
rupper <- c(1000, 2.1, 4, 5, 15)

# upper and lower bounds of the columns
clower <- c(2.5, 0, 0, 0, 0.5, 0, 0, 0)
cupper <- c(1000, 4.1, 1, 1, 4, 1000, 1000, 4.3)

# constraint matrix
ia <- c(0, 4, 0, 1, 1, 2, 0, 3, 0, 4, 2, 3, 0, 4)
ja <- c(0, 2, 4, 6, 8, 10, 11, 12, 14)
ar <- c(3.0, 5.6, 1.0, 2.0, 1.1, 1.0, -2.0, 2.8,
        -1.0, 1.0, 1.0, -1.2, -1.0, 1.9)

# direction of optimization
setObjDirCLP(lp, 1)

# load problem data
loadProblemCLP(lp, ncols, nrows, ia, ja, ar,
               clower, cupper, obj, rlower, rupper)

# solve lp problem
solveInitialCLP(lp)

# retrieve the results
getSolStatusCLP(lp)
getObjValCLP(lp)
getColPrimCLP(lp)

# remove problem object
delProbCLP(lp)

Example output

using COIN OR Clp version 1.15.5
Coin0506I Presolve 2 (-3) rows, 3 (-5) columns and 6 (-8) elements
Clp0006I 0  Obj 3.5 Dual inf 2.9473683 (1)
Clp0006I 1  Obj 3.2368421
Clp0000I Optimal - objective value 3.2368421
Coin0511I After Postsolve, objective 3.2368421, infeasibilities - dual 0 (0), primal 0 (0)
Clp0032I Optimal objective 3.236842105 - 1 iterations time 0.002, Presolve 0.00
[1] 0
[1] 0
[1] 3.236842
[1] 2.5000000 0.0000000 0.0000000 0.6428571 0.5000000 4.0000000 0.0000000
[8] 0.2631579

clpAPI documentation built on Oct. 28, 2021, 5:08 p.m.