Package net.pricefx.formulaengine.scripting

Interface RContext

All Superinterfaces:

AutoCloseable, Closeable

public interface RContext
extends Closeable

Method Summary

Modifier and Type	Method	Description
void	assign(String var, Object value)	Assigns a value to a variable in R.
REXP	eval(String expr)	Parses and evaluates an R expression and returns the result.
REXP	get(String var)	Retreives a value from R
String[]	names(String var)	Often in R, results have a 'names' attribute, for example the parameter names in an lm() regression
void	plot(String expr, String fileName)	Future functionality - Not yet implemented!
String	print(String var)	When evaluating an expression in R some output may be printed as a side effect, such as by lm().

Methods inherited from interface Closeable

close

Method Detail

assign

void assign(String var,
            Object value)

Assigns a value to a variable in R. The following types can be assigned

• String[]
• int[]
• double[]
• REXP
• Matrix2D

A value of type REXP would be one obtained from R with an eval or get call. A Matrix2D object is the result of a PA query: DatamartContext.executeQuery(net.pricefx.formulaengine.DatamartContext.Query)

Parameters:

var - Variable to assign to

value - Value(s) to assign

eval

REXP eval(String expr)

Parses and evaluates an R expression and returns the result. An expression can be as short as or as long as needed (i.e. a whole script).

Parameters:

expr - The expression, as string, to evaluate

Returns:

The resulting expression or null in case of an error

get

REXP get(String var)

Retreives a value from R

Parameters:

var - The variable to retreive the value from

Returns:

The resulting expression

names

String[] names(String var)

Often in R, results have a 'names' attribute, for example the parameter names in an lm() regression

Parameters:

var - The variable to retreive the names from

Returns:

The names array, or null if there is no such attribute

print

String print(String var)

When evaluating an expression in R some output may be printed as a side effect, such as by lm(). While not structured data, it may be useful to capture this output to show as a calculation result in the UI, or merely for logging purposes.

Parameters:

var - The variable to print, i.e. where that expression was assigned to

Returns:

The printed output as a string

plot

void plot(String expr,
          String fileName)

Future functionality - Not yet implemented!

Parameters:

expr -

fileName -