Run R script with start.process in .net

Question

I want to run an r script in vb.net which saves data in a .csv file. Till now i found the following approaches:

dim strCmd as String
strCmd = "R CMD BATCH" + "C:\test.R"
process.start("CMD.exe", strCmd

apparently this should work but in my case the cmd pops up (lokated in my debug folder) and nothing happens.

Another way i tried was

process.start("Rgui.exe", "C:\test.R")

Error Message: Argument "C:\test.R" ignored

this is not working either.

for my r script i just used an example

sink()
setwd("C:/")
x <- data.frame(a = I("a \" quote"), b = pi)
sink(test.csv)

Answer 1

this is how it works for me:

        Dim myprocess As New Process
        myprocess.StartInfo = New ProcessStartInfo("C:\Program Files (x86)\R\R-2.6.2\bin\R.exe", "CMD BATCH C:/Users/test/test3.R C:/Users/test/testout.csv")
        myprocess.Start()

second approach (first app. doesnt give me a good csv output so here this is a workaround):

    Dim proc = New Process
    proc.StartInfo.FileName = "C:\Program Files (x86)\R\R-2.6.2\bin\Rscript.exe"
    proc.StartInfo.WorkingDirectory = "C:\Program Files (x86)\R\R-2.6.2\bin"
    proc.StartInfo.Arguments = "C:/Users/Desktop/RtoVB/test4.r"
    proc.StartInfo.UseShellExecute = True
    proc.StartInfo.RedirectStandardOutput = False
    proc.Start()

Answer 2

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();
                    proc.Close();
                }

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