R support > RObject methods

You can get RObject using R facade predefined object in JavaScript.

Each RObject object provides the set of methods:

•	void newSession() - create new R session, all variables in previous context will be removed.

Example:

r.newSession();

•	void saveSession(String name) - associate current context with name and save it on file system. Context can be restored later with openSession function

Example:

r.saveSession("mySession");

•	void openSession(String name) - remove current R variables and load context from file system by name.

Example:

r.openSession("mySession");

•	void voidEval(String expression) - evaluate R expression in R environment without result returning.

Example:

r.voidEval("a <- 10"); //create variable in R context with integer value

•	REXP eval(String expression) - evaluate R expression in R environment. The parameter of this method is string with R script and it returns object as a result of the last R commend.

Example:

var d = rObject.eval("rnorm(2)"); //return array of double

•	void assignObject(String varName, Object value) - assign Javascript object to R environment with specified variable name.

Example:

rObject.assignObject("a", [1,2,3]); //add array variable "a" to R environment

•	void help(String expression) - looks for help in R environment and display it in BioUML environment.

Example:

rObject.help("data"); //display Data Sets help page from R

Complete example

Here is a complete JavaScript example of R session in BioUML.

var rObject = R.connect("server.biouml.org", 80); //get remote RObject

print(rObject); //print rObject to check R availability

rObject.newSession(); //clean R context

rObject.voidEval("x=0;for(i in 1:100) {x = x+i;}); //execute set of commands

var x = rObject.eval("x"); //get x value from R

print(x); //print the result to console

rObject.saveSession("testSession"); //save current variables state

To use x variable value next time you can use script like this:

var rObject = R.connect("server.biouml.org", 80); //get remote RObject

rObject.openSession("testSession"); //load saved R session

var x = rObject.eval("x"); //get variable from R

print(x); //print x value to console