2011/07/06

Yet another way to use R in Excel for .NET programmer

I wrote the article whose title is "Another way to use R in Excel for .NET programmer" last night.
In that article, We need to use IDE to write C# program.

On ther other hand, Excel-DNA give us easier way to create XLL.
Let me show you one example.

In last post, I downloaded two libraries.

  1. Excel-DNA
  2. R.NET

If you don't download these files yet, please do it.
And, put the files which I showed below together into some folder.
I changed the file name of ExcelDna.xll and ExcelDna.dna to SimpleExample.xll and SimpleExample.dna.
It is no problem for you to change these names as you like.

Next, Please copy and paste below codes to SimpleExample.dna by notepad or such a editor and save & close dna file.

<DnaLibrary RuntimeVersion="v4.0" Name="My First XLL" Language="CS">
<ExternalLibrary Path="R.NET.dll" />
<Reference Name="R.NET" />
<![CDATA[

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ExcelDna.Integration;
using RDotNet;

namespace CSLib
{
    public class CSLib
    {
        static REngine rengine = null;
        static CSLib()
        {
            // Set the folder in which R.dll locates.
            REngine.SetDllDirectory(@"C:\Program Files\R\R-2.13.0\bin\i386");
            rengine = REngine.CreateInstance("RDotNet", new[] { "-q" });
        }            
        [ExcelFunction(Description = "get random numbers obey to normal distribution")]
        public static double [] MyRnorm(int number)
        {
            return (rengine.EagerEvaluate("rnorm(" + number + ")").AsNumeric().ToArray<double>());
        }
    }
}

]]>
</DnaLibrary>



If you use or install another version R, modify "SetDllDirectory" function call.

Lanch SimpleExample.xll and create new Excel sheet. As you'll see below, you can use your own function defined in C# language !



Enjoy !

*R.NET seems to be compiled with .NET framework 4.0. you may have to install these to try this example.

2011/07/05

Another way to use R in Excel for .NET programmer

As you know, RExcel give us a way to combine R with Excel.
But, It just bothering to install some COMs and maybe not be programming but excel manipulation!

If you are a .NET programmer, there is another way to call R from Excel.
I would like to show you simple example.
We need to two libraries to do that.
  1. Excel-DNA
  2. R.NET
First, you download ExcelDNA from here.
And, go to "Distribution" folder.



you just need only three files(ExcelDna.dna, ExcelDna.xll, ExcelDna.Integration.dll) in this folder.
(I assume that your OS is 32bit windows.)
Second, you download R.NET from here.

you can set(or copy) these files any folder as you like.

Next, you start up your IDE. I used VC# this time.
Of-course, you can use other .NET languages like a VB.NET.

Create new project, choice "Class library" as template and wrote program as below.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ExcelDna.Integration;
using RDotNet;

namespace CSLib
{
    public class CSLib
    {
        static REngine rengine = null;
        static CSLib()
        {
            // Set the folder in which R.dll locates.
            REngine.SetDllDirectory(@"C:\Program Files\R\R-2.13.0\bin\i386");
            rengine = REngine.CreateInstance("RDotNet", new[] { "-q" });
        }            
        [ExcelFunction(Description = "get random numbers obey to normal distribution")]
        public static double [] MyRnorm(int number)
        {
            return (rengine.EagerEvaluate("rnorm(" + number + ")").AsNumeric().ToArray());
        }
    }
}

In this case, I defined the function which generates random numbers obey standard normal  distribution. If you use or install another version R, modify "SetDllDirectory" function call.
All source code and solution files are here(github).

Next, Add R.NET.dll and ExcelDna.Integration.dll to your project as reference.
Now, Everything is ready. Let's compile !

After compile, you have to modify your ExcelDna.dna file.
Edit this file with notepad like below.
















(v4.0 means your version of .NET framework. modify this number if you need)
(If your DLL's relative-path is not "CSLib.dll" from ExcelDNA.xll, you have to correct this name)
(I deployed CSLib.dll, ExcelDna.xll, ExcelDna.dna in the same folder)

After that, double-click your ExcelDna.xll and create new Excel sheet.
As you'll see below, you can use your own function defined in C# language !



Enjoy !