"Pbm with retrieving an R function from repository"

fle

Hi,
thank you for the development of R Extension, it looks very cool.

I have done the installation without problem (on XP) and can run the R demos Generate Vector and Append Vectors.
The R console also seems to work fine.

However, using the R console, I  tried to write a simple function defined like this
x<-function(){
return(rnorm(1000,100,16))
}

and store x in the repository, like in the demo video.

Using the R console, it works fine, I can retrieve the file where x has been stored, and execute the function.

But I have problem using the Retrieve operator :
first, when I drag the object from repository to the Main Process window, I don't get the R script in a result window
then I add a Execute Script operator,, connect it to the Retrieve operator, and get the following error "The given object null cannot be translated to R"
finally I cannot add an input name in the Execute operator (it does not save anything).

I have tried putting the code of the R function directly in the Execute operator, and it worked.

Do you have any idea regarding what could be wrong with the Retrive operator ?
thank you for your help.

land

Hi,
ok, I will try to summarize how this is supposed to work:

You can save arbitrary functions or data, whatever fits into a variable in R into a RapidMiner Object. This object then encapsulates the specific variable. You can do this either in the console or by defining a result inside a R Script Operator. In the console you can do this in the variable view. A speciality there is, that you can save more than one variable at once. This is done by grouping the variable in a RapidMiner Object Collection. This collection can be loaded again in the console, but cannot (!) be forwarded to the script operator! In the script operator you need to assign each object that is forwarded a single name with that it is accessible in the R Script. Since the collection would contain multiple variables, this way isn't possible, because we can't store them all under the same name!
In a process you can define Results in the script operator. These will be delivered as the type you specified. If you choose "Generic R Result" this can be any variable. Then you will have this RapidMiner Object again, containing the variable. You can save it by using the "Store" operator.

The content of the variables containing functions, data or results, saved in the console or via the "Store" operator, can be loaded again to a process using a "Retrieve" operator. Then they can be forwarded to any script operator and made available under any variable name you want. Then they are accessible inside this script with the name you chose.

If you stored a variable in such an RapidMiner object they become immutable. You cannot apply any changes on it. This on the one hand ensures that your results are save (unless you overwrite them) and give you a possibility to build up a system of functions that combine to some sort of API and can be shared with others by accessing the same repository. On the other hand this makes it difficult to manage your code base, because you have to store it separately somewhere else. We will address this issue with one of the next releases of the R Extension, so that we can provide a more integrated Development Environment.

Greetings,
  Sebastian