Cannot find function via Rserve but it is visible in R

Question

I am trying the Java client to rserve. I have a function defined in R as follows:

bar <- function(x) { x+1 }

executing this inside R gives the following (expected) output:

> bar(1)
[1] 2

however, executing the following Java code:

public static void main(String[] args) throws REXPMismatchException, REngineException {
  RConnection c = new RConnection();
  REXP x = c.eval("try({bar(1)}, silent=TRUE)");
  System.out.println(x.asString());

}

gives the following output:

Error in try({ : could not find function "bar"

inside the R console the following message is output:

> Error: could not find function "bar"

Is there something I need to do to make my function visible to Rserve?

Steve

Answer 1

You are defining your function inside of a different workspace / process. Rserve and R do not share the same process space so declaring your method in one will not make it appear in Rserve workspace.

public static void main(String[] args) throws REXPMismatchException, REngineException {
  RConnection c = new RConnection();
  REXP x = c.eval("try({bar <- function(x) { x+1 }; bar(1)}, silent=TRUE)");
  System.out.println(x.asString());
}

Answer 2

i had similar issue, you need to store your R code in a file which is called when Rserve is started (within same process), steps to be taken:

1. Create file with your R code (functions etc. ...) and name it for example filename.R

2. Create Rserv.conf file and paste there line

   source /path to the file with R code/filename.R

3. Run R serve using command

   Rserve(debug = TRUE, args='--no-save --RS-conf /path to the Rserv file/Rserv.conf')

it should works ...