Version: 1.0-2
Title: 'NEOS' Plug-in for the 'R' Optimization Interface
Description: Enhances the 'R' Optimization Infrastructure ('ROI') package with a connection to the 'neos' server. 'ROI' optimization problems can be directly be sent to the 'neos' server and solution obtained in the typical 'ROI' style.
Imports: stats, methods, utils, ROI (≥ 1.0-0), xmlrpc2, xml2
Suggests: slam
License: GPL-3
Encoding: UTF-8
URL: https://roigrp.gitlab.io, https://gitlab.com/roigrp/solver/ROI.plugin.neos
RoxygenNote: 7.2.3
NeedsCompilation: no
Packaged: 2023-11-25 21:38:34 UTC; f
Author: Ronald Hochreiter [aut], Florian Schwendinger [aut, cre]
Maintainer: Florian Schwendinger <FlorianSchwendinger@gmx.at>
Repository: CRAN
Date/Publication: 2023-11-25 22:10:02 UTC

Linear Problem 1

Description

maximize \ \ 2 x_1 + 4 x_2 + 3 x_3

subject \ to:

3 x_1 + 4 x_2 + 2 x_3 \leq 60

2 x_1 + x_2 + 2 x_3 \leq 40

x_1 + 3 x_2 + 2 x_3 \leq 80

x_1, x_2, x_3 \geq 0

Examples

## Not run: 
library(ROI)
mat <- matrix(c(3, 4, 2,
                2, 1, 2,
                1, 3, 2), nrow=3, byrow=TRUE)
x <- OP(objective = c(2, 4, 3),
        constraints = L_constraint(L = mat,
                                   dir = c("<=", "<=", "<="),
                                   rhs = c(60, 40, 80)),
        maximum = TRUE)


opt <- ROI_solve(x, solver = "neos", method = "scip")
opt
## Optimal solution found.
## The objective value is: 7.666667e+01
solution(opt)
## [1]  0.000000  6.666667 16.666667

## End(Not run)

Neos Control Variables

Description

The control variables for ROI.plugin.neos.

Usage

neos_control(
  method = "auto",
  wait = TRUE,
  email = "",
  password = "",
  user = "rneos",
  dry_run = FALSE,
  options = "",
  parameters = "",
  gdx = "",
  restart = "",
  wantgdx = "",
  wantlst = "",
  wantlog = "",
  comments = ""
)

Arguments

method

a chracter string giving the name of the solver to be selected on the NEOS server.

wait

a logical indicating whether the R interpreter should wait for the command to finish, or run it asynchronously. If TRUE ROI returns an object of class "neos_job".

email

a character string giving the email address.

password

a character string giving the account password.

user

a character string giving the username.

dry_run

a logical if TRUE ROI returns the solver call.

options

a character string (default is "") passed to options tag of the GAMS solver template.

parameters

a character string (default is "") passed to parameters tag of the GAMS solver template.

gdx

a character string (default is "") passed to gdx tag of the GAMS solver template.

restart

a character string (default is "") passed to restart tag of the GAMS solver template.

wantgdx

a character string (default is "") passed to wantgdx tag of the GAMS solver template.

wantlst

a character string (default is "") passed to wantlst tag of the GAMS solver template.

wantlog

a character string (default is "") passed to wantlog tag of the GAMS solver template.

comments

a character string (default is "") passed to comments tag of the GAMS solver template.

Translate to GAMS

Description

Translate a ROI OP to GAMS code. This function can translate optimization problems with linear or quadratic objective and linear or quadratic constraints.

Usage

to_gams(x)

Arguments

x

an ROI object of class OP.

Value

a character string giving the GAMS optimization model.

Examples

library("ROI")
mat <- matrix(c(3, 4, 2, 2, 1, 2, 1, 3, 2), nrow=3, byrow=TRUE)
x <- OP(objective = c(2, 4, 3),
        constraints = L_constraint(L = mat,
                                   dir = c("<=", "<=", "<="),
                                   rhs = c(60, 40, 80)),
        bounds = V_bound(ui = seq_len(3), ub = c(1000, Inf, 1000), nobj = 3),
        maximum = TRUE)
writeLines(to_gams(x))