Getting started

Installation

The AMPL API can function as an add-on to any existing AMPL installation. If you do not yet have an AMPL installation on the computer where you will be working with the API, see our demo page or trial page to download a working version that can be installed quickly.

In order to install the latest version of the R API you just need to run:

install.packages("Rcpp", type="source")
install.packages("https://ampl.com/dl/API/rAMPL.tar.gz", repos=NULL)

Alternatively, you can install a specific version as follows:

install.packages("https://ampl.com/dl/API/future/<version>/rAMPL_<version>.tar.gz", repos=NULL)

Initial test

To begin, open a R console and set the working directory to the directory containing the examples:

setwd(paste(find.package("rAMPL"), "examples", sep="/"))

To complete an initial test, run firstexample.R with

source("firstexample.R")
firstexample(solver=NULL)

where optionally solver="<solver>" is the name of a solver that has been installed with AMPL. (If a solver is not specified, AMPL’s default choice will be used.) This will solve several small diet problems and then display the optimal amounts of the foods from the last solution.

Note that the folder containing the AMPL executable should be in the system search path. Otherwise, the error message “AMPL could not be started” will be shown. If the AMPL installation directory is not in the system search path, you can add it passing a new Environment to AMPL as follows:

ampl <- new(AMPL, new(Environment, "full path to the AMPL installation directory"))

Note that you may need to escape backslashes (e.g., ‘C:\\ampl\\ampl.mswin64’) if included in the path.

Development

Load the rAMPL library with

library(rAMPL)

Together with your existing AMPL implementation, this will provide the full object library and access to all AMPL functions. Please make sure that the folder containing the AMPL executable is in the system search path.

Deployment

To deploy AMPL API applications to users who do not have their own AMPL installations, include with your application the AMPL executable (ampl or ampl.exe), and the rAMPL library. Note that the folder containing the AMPL executable should be in the system search path.