Hi Dan,
Most of the reason I haven't released it yet is just that the code is very
messy... but perhaps I can send you some stuff as an example. The main
thing I did structurally is I created the main window of the project (which
I just called main window - I'm strikingly uncreative) and then I have a
classes called R and RCommand.
The MainWindow form stores a public shared variable called R. Then, when you
load the form (start the application) it launches and connects to the DCOM
server.
Public Class MainWindow
Public Shared R As R
Private Sub MainWindow_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
Me.webDisplay.DocumentText = ""
LoadR()
End Sub
Private Sub LoadR()
Try
R = New R
Catch
MsgBox("This application requires the (D)COM server available
from the comprehensive R archive network. Please install (D)COM and restart
this application. If you have already installed the (D)COM server, then
there appears to be a problem with that application. Please try
re-installing the (D)COM server.")
Me.Close()
End Try
End Sub
....
End Class
The "R" class you see here is one that I wrote... it looks like this...
Imports STATCONNECTORSRVLib
Imports StatConnectorCommonLib
Imports System.Collections.ObjectModel
Public Class R
Dim RServ As StatConnector
Sub Close()
RServ.Close()
End Sub
Public Sub New()
RServ = New StatConnector
RServ.Init("R")
End Sub
Public Function Evaluate(ByVal command As String) As Object
Dim rtrObj As Object
Try
rtrObj = RServ.Evaluate(command)
Catch ex As Exception
rtrObj = Nothing
End Try
Return rtrObj
End Function
....
End Class
If you're familiar with the DCOM server, basically you should see what's
happening... When the MainWindow opens, that form creates a new R class that
never closes until it is explicitly closed. That R class, when it opens,
creates a connection to R using the DCOM server. In that class are functions
that replicate the various things the DCOM server does (such as evaluate).
These functions then return whatever R returns to them..
The various Try/Catch blocks basically will fail if the DCOM server cannot
connect - that's how that message box works. If the program can't connect
to the DCOM server it will give that nice response and then close.
Because "R" is a publicly shared variable in the MainWindow, from anywhere
in the application you can type "MainWindow.R.Evaluate('2+2')" and it will
execute and return the object result.
Now that's where things get a bit trickier... DCOM returns things as normal
datatypes and you have to basically respond to them based on what they
are... For this, I would recommend looking at the sort of data you need to
get back and start playing with it... I used a somewhat complex HTML output
so I spend a bunch of time in my code converting those results into an HTML
format- you'd probably not want to do this... So yeah, I'd play around with
what you need - you'll probably see what I'm talking about... Since it's
returning a generic object, you don't know right away what type of object it
is, so you do things like... "objRtr.GetType.ToString" and that lets you
read the type, then you respond based on the type of object it returns...
For example, if it's just a string, you can do "rtrText = CType(objRtr,
String).ToString".
I'm going to send this to the DCOM listserv as well in case anybody else is
interested in my example... Dan, I've moved your address to the BCC so it
won't be shared...
Hope this helps,
Mike
_____
From: Dan Georgescu [mailto: XXXXX ]
Sent: Tuesday, December 18, 2007 6:18 AM
To: [EMAIL PROTECTED]
Subject: R.net
Hi Mike,
I am trying to write a .Net GUI for an economic scenario generator. The ESG
will be in R. I have been trying to link R and .net without much luck so far
- my programming skills are not quite there yet. Your front-end does this
and I was wondering whether I could have the source code for your project to
speed things along. I hope this is alright - you mention in your post to the
R D(COM) mailing list that you might be releasing this as open source in the
future, so I hope I am not being too cheeky.
Many thanks,
Dan
_____
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