R and C# on Windows

The following page offers a good introduction, but some information is missing. So I thought it would be useful to add some more instructions, especially for deployment on client systems on which R has not been installed yet.

http://www.codeproject.com/KB/cs/RtoCSharp.aspx

Here’s a list of issues:

1. R requires Administrator rights when you install it (as described in the R Administration guide). This also applies when you want to install add-ons. R itself does not have these permissions, so if you install an add-on from within R, you will get an “access denied” error (to install an add-on, you can use the R gui,  Packages->Install package(s) …). A workaround is to make the R program directory writable to everyone. Maybe you can also try to run R itself as administrator when you need to install a package, but I haven’t tried this yet. This would probably be a better solution.
2. Anyway, on windows, the install procedure is not actually an install procedure. You only get a zip file in a temporary directory. So to really install an add-on, you need to copy the extracted add-on folder and copy it to the Rlibrary. Note that this also requires write access to the R installtion folder.

Here’s a summary of what you need to do to get R working:

1. Download the rscproxy package http://www.freestatistics.org/cran/bin/windows/contrib/r-release/rscproxy_1.2-0.zip, unzip it and install the rscproxy directory in your Rlibrary directory.
2. Download R_Scilab_DCOM3.0-1B5.exe from http://www.freestatistics.org/cran/contrib/extra/dcom/R_Scilab_DCOM3.0-1B5.exe (you coulds also use another mirror), and install it.
3. To use R, add a reference to your C# project to STATCONNECTORCLNTLib, StatConnectorCommonLib, and STATCONNECTORSRVLib (this is to get full functionality, for the client to work, you only need STATCONNECTORSRVLib).
4. Use the STATCONNECTORSRVLib.StatConnectorClass to interface with R.

Here’s some example code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NUnit.Framework;

//COM references
using STATCONNECTORCLNTLib;
using StatConnectorCommonLib;
using STATCONNECTORSRVLib;
using System.IO;

namespace RConnector.Tests.Integration
{
    [TestFixture]
    public class TestConnectivityWithR
    {

        [Test]
        public void Open_Close()
        {
            StatConnectorClass RConnector = new StatConnectorClass();
            RConnector.Init(“R”);
            RConnector.Close();
        }

        [Test]
        public void Send_Receive_Data_()
        {
            StatConnectorClass RConnector = new StatConnectorClass();
            RConnector.Init(“R”); 
           // Data we are going to pass
            int n = 20;
            // Cast C# type to R type
            RConnector.SetSymbol(“n1″, n); 
            // The cast value n to n1 is now being used in R
            RConnector.Evaluate(“x1 <- rnorm(n1)”); 
            // We get back the value of x1, but it needs to be cast
            // to an array of doubles
            object o = RConnector.GetSymbol(“x1″);
            double[] random = (double[])o;
            foreach (double d in random)
            {
                Console.WriteLine(d);
            }
        }

        [Test]
        public void Plot_CSharpInput_Simple()
        {
            StatConnectorClass RConnector = new StatConnectorClass();
            RConnector.Init(“R”);
            double[] input = new double[] { 1.0, 2.0, 3.0, 2.0, 1.0};
            RConnector.SetSymbol(“input”, input);
            RConnector.EvaluateNoReturn(“hist(input)”);
            RConnector.EvaluateNoReturn(
                “savePlot(filename = \”" +
                @”C:\\Users\\Joachim\\Documents\\Debug\\Plot_CSharpInput.eps” + “\”, ” + 
                “type = \”eps\”, device = dev.cur(), restoreConsole = TRUE )”
            ); 
            //RConnector.Close();
        }

 

        [Test] public void Plot_CSharpInput_Simple_WithColors_Rainbow()
        {
            StatConnectorClass RConnector = new StatConnectorClass();
            RConnector.Init(“R”);
            double[] input = new double[] {1.0, 2.0, 3.0, 2.0, 1.0};
            RConnector.SetSymbol(“input”, input);
            RConnector.EvaluateNoReturn(“barplot(input, main=\”Foobar\”, xlab=\”Value\”, ylab=\”Frequency\”, col=rainbow(7))”);
            RConnector.EvaluateNoReturn(“legend(\”topleft\”, c(\”Hello\”, \”World\”), cex=0.6, bty=\”n\”, fill=rainbow(5))”);
            RConnector.EvaluateNoReturn(
                “savePlot(filename = \”" +
                @”C:\\Users\\Joachim\\Documents\\Debug\\Plot_CSharpInput.eps” + “\”, “ +
                “type = \”eps\”, device = dev.cur(), restoreConsole = TRUE )”);
            //RConnector.Close();
        }

    }
}

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