[R] Einlesen von Daten unter R

[Torsten Steuernagel]

Hello Oscar,

I reply in English because that's the language used on this list.

> Die Verwendung der beiden Programme Labview und R  ist unpraktisch. Es
> stellt sich daher die Frage, ob serielle Daten auch über R eingelesen
> werden können oder ob das R-Programm in ein Labview-Programm eingebaut
> werden kann.

I don't know Labview so I can't say anything about the possibility to integrate R into 
Labview or vice versa. I did a quick search on CRAN but haven't found anything related 
to Labview. If you simply want to avoid Excel, you might check if Labview supports other 
output formats than Excel. Most applications are able to write data to plain text files 
which R handles easily.

I don't think that there is a special serial communications library for R but since the 
serial devices are treated as special files on Win32 (I assume you're using Windows, on 
Unix it's similar), you can use R's I/O functions to access your COM ports. I suggest you 
read the help for connections (? connections) to get an overview of R's I/O connections 
as well as the help for functions like cat, write, scan, readBin, writeBin etc. To get an 
idea, the following code will dial my internet provider (T-Online) using my Notebook's 
modem connected to COM1:

handle <- file("com1", open="r+b")
cat("ATD0191011\r\n", file=handle)
close(handle) 

If that approach will work for you depends on the requirements of the device you want 
to control. R, as far as I know, doesn't provide functions that let you configure your 
serial port (i.e. baut rate, timeouts, handshakings and so on). You might try to configure 
those from a Windows command line (aka "DOS box") using the MODE command. 
Otherwise, you need to write some C functions that interface with the Windows API to 
set up the device control block accordingly. Furthermore, you should also read the 
comments on blocking vs. non-blocking I/O modes in the help for connections.
 
> Ich wäre sehr froh, wenn Sie mir in dieser Sache behilflich sein
> könnten. Ebenso möchte ich gerne Näheres über R erfahren. Zur
> Verfügung steht mir bisher das bekannte Büchlein über R und eine
> Beschreibung "Message Boxes in R TclTk".

You should check the "Publications" section on the R homepage (http://www.r-
project.org/doc/bib/R-publications.html) for a list of R and S related publications. As a 
start I recommend reading the manuals that come with R, especially "An Introduction to 
R".

BFN,

Torsten