c# - Executing R script programmatically

Question

I have a C# program that generates some R code. Right now I save the script to file and then copy/paste it into the R console. I know there is a COM interface to R, but it doesn't seem to work with the latest version of R (or any version after 2.7.8). Is there some way I can just programmatically execute the R script from C# after saving it to file?

Answer 1

Here is the class I recently wrote for this purpose. You can also pass in and return arguments from C# and R:

/// <summary>
/// This class runs R code from a file using the console.
/// </summary>
public class RScriptRunner
{
    /// <summary>
    /// Runs an R script from a file using Rscript.exe.
    /// Example:  
    ///   RScriptRunner.RunFromCmd(curDirectory + @"ImageClustering.r", "rscript.exe", curDirectory.Replace('\','/'));
    /// Getting args passed from C# using R:
    ///   args = commandArgs(trailingOnly = TRUE)
    ///   print(args[1]);
    /// </summary>
    /// <param name="rCodeFilePath">File where your R code is located.</param>
    /// <param name="rScriptExecutablePath">Usually only requires "rscript.exe"</param>
    /// <param name="args">Multiple R args can be seperated by spaces.</param>
    /// <returns>Returns a string with the R responses.</returns>
    public static string RunFromCmd(string rCodeFilePath, string rScriptExecutablePath, string args)
    {
            string file = rCodeFilePath;
            string result = string.Empty;

            try
            {

                var info = new ProcessStartInfo();
                info.FileName = rScriptExecutablePath;
                info.WorkingDirectory = Path.GetDirectoryName(rScriptExecutablePath);
                info.Arguments = rCodeFilePath + " " + args;

                info.RedirectStandardInput = false;
                info.RedirectStandardOutput = true;
                info.UseShellExecute = false;
                info.CreateNoWindow = true;

                using (var proc = new Process())
                {
                    proc.StartInfo = info;
                    proc.Start();
                    result = proc.StandardOutput.ReadToEnd();
                }

                return result;
            }
            catch (Exception ex)
            {
                throw new Exception("R Script failed: " + result, ex);
            }
    }
}

NOTE: You may want to add the following to you code, if you are interested in cleaning up the process.

proc.CloseMainWindow(); proc.Close();