org.ddahl.rscala

Class RClient4Java

java.lang.Object

org.ddahl.rscala.RClient4Java

public class RClient4Java
extends java.lang.Object

A Java interface to an R interpreter. In a Java application, an instance of this class is created as shown below.

 
 import org.ddahl.rscala.RClient4Java;
 
 public class Example {
 
   public static void main(String[] args) {
 
     RClient4Java R = new RClient4Java();
  
     double a = R.evalD0("rnorm(8)");
     double[] b = R.evalD1("rnorm(8)");
     double[][] c = R.evalD2("matrix(rnorm(8),nrow=4)");
 
     R.eval("v <- rbinom(8,size=10,prob=0.4)\n"+
            "m <- matrix(v,nrow=4)",true);
 
     Object[] v1 = R.get("v");
     int[] v2 = (int[]) R.get("v")[0];   // This works, but is not very convenient
     int v3 = R.getI0("v");      // Get the first element of R's "v" as a Int
     int[] v4 = R.getI1("v");    // Get R's "v" as an int[]
     int[][] v5 = R.getI2("m");  // Get R's "m" as an int[][]
 
     int[] aa = {5,6,4};
     R.set("a",aa);
 
     R.eval("b <- matrix(NA,nrow=3,ncol=2)");
     for ( int i=0; i<3; i++ ) {
       int[] bb = {2*i,2*i+1};
       R.set("b",bb,""+(i+1)+",",true);
     }
 
     R.eval("myList <- list()");
     String[] cc = {"David","Grace","Susan"};
     R.set("myList",cc,"'names'",false);
     int[] dd = {5,4,5};
     R.set("myList",dd,"'counts'",false);
     R.eval("print(myList)");
 
   }
 
 }

 

 

Constructor Summary

Constructors

Constructor and Description
RClient4Java()
RClient4Java(java.lang.String rCmd)
RClient4Java(java.lang.String rCmd, boolean serializeOutput)
RClient4Java(java.lang.String rCmd, boolean serializeOutput, boolean rowMajor)
RClient4Java(java.lang.String rCmd, boolean serializeOutput, boolean rowMajor, int port)
RClient4Java(java.lang.String rCmd, boolean serializeOutput, boolean rowMajor, int port, boolean debug)

Method Summary

Modifier and Type	Method and Description
void	eval(java.lang.String snippet) Calls and returns eval(snippet).
java.lang.Object	eval(java.lang.String snippet, boolean evalOnly, boolean asReference) Evaluates snippet in the R interpreter.
double	evalD0(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getD0.
double[]	evalD1(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getD1.
double[][]	evalD2(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getD2.
int	evalI0(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getI0.
int[]	evalI1(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getI1.
int[][]	evalI2(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getI2.
boolean	evalL0(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getL0.
boolean[]	evalL1(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getL1.
boolean[][]	evalL2(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getL2.
byte	evalR0(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getR0.
byte[]	evalR1(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getR1.
byte[][]	evalR2(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getR2.
java.lang.String	evalS0(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getS0.
java.lang.String[]	evalS1(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getS1.
java.lang.String[][]	evalS2(java.lang.String snippet) Calls eval(snippet,true) and returns the result using getS2.
void	exit() Closes the interface to the R interpreter.
java.lang.Object[]	get(java.lang.String identifier) Returns the value of identifier in the R interpreter.
double	getD0(java.lang.String identifier) Calls get(identifier,false) and converts the result to a double.
double[]	getD1(java.lang.String identifier) Calls get(identifier,false) and converts the result to a double[].
double[][]	getD2(java.lang.String identifier) Calls get(identifier,false) and converts the result to a double[][].
int	getI0(java.lang.String identifier) Calls get(identifier,false) and converts the result to an int.
int[]	getI1(java.lang.String identifier) Calls get(identifier,false) and converts the result to an int[].
int[][]	getI2(java.lang.String identifier) Calls get(identifier,false) and converts the result to an int[][].
boolean	getL0(java.lang.String identifier) Calls get(identifier,false) and converts the result to a boolean.
boolean[]	getL1(java.lang.String identifier) Calls get(identifier,false) and converts the result to a boolean[].
boolean[][]	getL2(java.lang.String identifier) Calls get(identifier,false) and converts the result to a boolean[][].
byte	getR0(java.lang.String identifier) Calls get(identifier,false) and converts the result to a byte.
byte[]	getR1(java.lang.String identifier) Calls get(identifier,false) and converts the result to a byte[].
byte[][]	getR2(java.lang.String identifier) Calls getR2(identifier,false) and converts the result to an byte[][].
java.lang.String	getS0(java.lang.String identifier) Calls get(identifier,false) and converts the result to a String.
java.lang.String[]	getS1(java.lang.String identifier) Calls get(identifier,false) and converts the result to a String[].
java.lang.String[][]	getS2(java.lang.String identifier) Calls get(identifier,false) and converts the result to a String[][].
void	set(java.lang.String identifier, java.lang.Object value) Equivalent to calling set(identifier, value, "", true).
void	set(java.lang.String identifier, java.lang.Object value, java.lang.String index, boolean singleBrackets) Assigns value to a variable identifier in the R interpreter.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RClient4Java

public RClient4Java()

RClient4Java

public RClient4Java(java.lang.String rCmd)

RClient4Java

public RClient4Java(java.lang.String rCmd,
                    boolean serializeOutput)

RClient4Java

public RClient4Java(java.lang.String rCmd,
                    boolean serializeOutput,
                    boolean rowMajor)

RClient4Java

public RClient4Java(java.lang.String rCmd,
                    boolean serializeOutput,
                    boolean rowMajor,
                    int port)

RClient4Java

public RClient4Java(java.lang.String rCmd,
                    boolean serializeOutput,
                    boolean rowMajor,
                    int port,
                    boolean debug)

Method Detail

exit

public void exit()

Closes the interface to the R interpreter. Subsequent calls to the other methods will fail.

eval

public void eval(java.lang.String snippet)

Calls and returns eval(snippet).

Parameters:

snippet - The snippet to be evaluated.

eval

public java.lang.Object eval(java.lang.String snippet,
                             boolean evalOnly,
                             boolean asReference)

Evaluates snippet in the R interpreter. Returns null if evalOnly. If !evalOnly, the last result of the R expression is converted if possible. Conversion to integers, doubles, booleans, and strings are supported, as are vectors (i.e. arrays) and matrices (i.e. retangular arrays of arrays) of these types. The static type of the result, however, is Any so using the method evalXY (where X is I, D, B, or S and Y is 0, 1, or 2) may be more convenient (e.g. evalD0).

Parameters:

snippet - The snippet to be evaluated.

evalOnly - An indicator of whether the snippet should be evaluated only, or if otehr steps should be performed.

asReference - If false and the conversion is supported, the result is converted. Otherwise, a reference is returned. e result is converted if `asReference` is `false` and the conversion is supported, otherwise a reference is returned.

Returns:

The evaluated Object.

evalI0

public int evalI0(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getI0.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated int.

evalD0

public double evalD0(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getD0.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated double.

evalL0

public boolean evalL0(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getL0.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated boolean.

evalS0

public java.lang.String evalS0(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getS0.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated string.

evalR0

public byte evalR0(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getR0.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated byte.

evalI1

public int[] evalI1(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getI1.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated int array.

evalD1

public double[] evalD1(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getD1.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated double array.

evalL1

public boolean[] evalL1(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getL1.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated boolean array.

evalS1

public java.lang.String[] evalS1(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getS1.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated string array.

evalR1

public byte[] evalR1(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getR1.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated byte array.

evalI2

public int[][] evalI2(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getI2.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated int matrix.

evalD2

public double[][] evalD2(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getD2.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated double matrix.

evalL2

public boolean[][] evalL2(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getL2.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated boolean matrix.

evalS2

public java.lang.String[][] evalS2(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getS2.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated String matrix.

evalR2

public byte[][] evalR2(java.lang.String snippet)

Calls eval(snippet,true) and returns the result using getR2.

Parameters:

snippet - The snippet to be evaluated.

Returns:

The evaluated byte matrix.

set

public void set(java.lang.String identifier,
                java.lang.Object value)

Equivalent to calling set(identifier, value, "", true).

Parameters:

identifier - The string of input to be set.

value - The value of the string.

set

public void set(java.lang.String identifier,
                java.lang.Object value,
                java.lang.String index,
                boolean singleBrackets)

Assigns value to a variable identifier in the R interpreter. Integers, doubles, booleans, and strings are supported, as are vectors (i.e. arrays) and matrices (i.e. retangular arrays of arrays) of these types. If index != "", assigned into elements of identifier are performed by using either single brackets (singleBrackets=true) or double brackets (singleBrackets=false).

Parameters:

identifier - The string of input to be set.

value - The value of the string.

index - A string containing the index values.

singleBrackets - A Boolean indicating whether or not to use single brackets.

get

public java.lang.Object[] get(java.lang.String identifier)

Returns the value of identifier in the R interpreter. The runtime type is an array whose first element is the value for the identifier and whose second element is String indicates the runtime type. Conversion to integers, doubles, booleans, and strings are supported, as are vectors (i.e. arrays) and matrices (i.e. retangular arrays of arrays) of these types. Using the method getXY (where X is I, D, B, or S and Y is 0, 1, or 2) may be more convenient (e.g. getD0).

Parameters:

identifier - The string of input to be set.

Returns:

The evaluated Object.

getI0

public int getI0(java.lang.String identifier)

Calls get(identifier,false) and converts the result to an int. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated int.

getD0

public double getD0(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a double. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated double.

getL0

public boolean getL0(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a boolean. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated boolean.

getS0

public java.lang.String getS0(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a String. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated String.

getR0

public byte getR0(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a byte. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated byte.

getI1

public int[] getI1(java.lang.String identifier)

Calls get(identifier,false) and converts the result to an int[]. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated int array.

getD1

public double[] getD1(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a double[]. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated double array.

getL1

public boolean[] getL1(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a boolean[]. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated boolean array.

getS1

public java.lang.String[] getS1(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a String[]. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated String array.

getR1

public byte[] getR1(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a byte[]. Integers, doubles, booleans, and strings are supported. Vectors (i.e. arrays) of these types are also supported by converting the first element. Matrices (i.e. rectangular arrays of arrays) are not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated byte array.

getI2

public int[][] getI2(java.lang.String identifier)

Calls get(identifier,false) and converts the result to an int[][]. Matrices (i.e. rectangular arrays of arrays) of integers, doubles, booleans, and strings are supported. Integers, doubles, booleans, and strings themselves are not supported. Vectors (i.e. arrays) of these types are also not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated int matrix.

getD2

public double[][] getD2(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a double[][]. Matrices (i.e. rectangular arrays of arrays) of integers, doubles, booleans, and strings are supported. Integers, doubles, booleans, and strings themselves are not supported. Vectors (i.e. arrays) of these types are also not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated double matrix.

getL2

public boolean[][] getL2(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a boolean[][]. Matrices (i.e. rectangular arrays of arrays) of integers, doubles, booleans, and strings are supported. Integers, doubles, booleans, and strings themselves are not supported. Vectors (i.e. arrays) of these types are also not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated boolean matrix.

getS2

public java.lang.String[][] getS2(java.lang.String identifier)

Calls get(identifier,false) and converts the result to a String[][]. Matrices (i.e. rectangular arrays of arrays) of integers, doubles, booleans, and strings are supported. Integers, doubles, booleans, and strings themselves are not supported. Vectors (i.e. arrays) of these types are also not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated string matrix.

getR2

public byte[][] getR2(java.lang.String identifier)

Calls getR2(identifier,false) and converts the result to an byte[][]. Matrices (i.e. rectangular arrays of arrays) of integers, doubles, booleans, and strings are supported. Integers, doubles, booleans, and strings themselves are not supported. Vectors (i.e. arrays) of these types are also not supported.

Parameters:

identifier - The string to be evaluated.

Returns:

The evaluated int matrix.