{

public void rWriteConsole(Rengine re, String text, int oType) {

System.out.print(text);

}

public void rBusy(Rengine re, int which) {

System.out.println("rBusy("+which+")");

}

public String rReadConsole(Rengine re, String prompt, int addToHistory) {

System.out.print(prompt);

try {

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

String s=br.readLine();

return (s==null||s.length()==0)?s:s+"\n";

} catch (Exception e) {

System.out.println("jriReadConsole exception: "+e.getMessage());

}

return null;

}

public void rShowMessage(Rengine re, String message) {

System.out.println("rShowMessage \""+message+"\"");

}

public String rChooseFile(Rengine re, int newFile) {

FileDialog fd = new FileDialog(new Frame(), (newFile==0)?"Select a file":"Select a new file", (newFile==0)?FileDialog.LOAD:FileDialog.SAVE);

fd.show();

String res=null;

if (fd.getDirectory()!=null) res=fd.getDirectory();

if (fd.getFile()!=null) res=(res==null)?fd.getFile():(res+fd.getFile());

return res;

}

public void rFlushConsole (Rengine re) {

}

public void rLoadHistory (Rengine re, String filename) {

}

public void rSaveHistory (Rengine re, String filename) {

}

public static void main(String[] args) {

// just making sure we have the right version of everything

if (!Rengine.versionCheck()) {

System.err.println("** Version mismatch - Java files don't match library version.");

System.exit(1);

}

System.out.println("Creating Rengine (with arguments)");

// 1) we pass the arguments from the command line

// 2) we won't use the main loop at first, we'll start it later

// (that's the "false" as second argument)

// 3) the callbacks are implemented by the TextConsole class above

Rengine re=new Rengine(args, false, new TextConsole());

System.out.println("Rengine created, waiting for R");

// the engine creates R is a new thread, so we should wait until it's ready

if (!re.waitForR()) {

System.out.println("Cannot load R");

return;

}

/* High-level API - do not use RNI methods unless there is no other way

try {

REXP x;

re.eval("data(iris)",false);

System.out.println(x=re.eval("iris"));

// generic vectors are RVector to accomodate names

RVector v = x.asVector();

if (v.getNames()!=null) {

System.out.println("has names:");

for (Enumeration e = v.getNames().elements() ; e.hasMoreElements() ;) {

System.out.println(e.nextElement());

}

}

// for compatibility with Rserve we allow casting of vectors to lists

RList vl = x.asList();

String[] k = vl.keys();

if (k!=null) {

System.out.println("and once again from the list:");

int i=0; while (i<k.length) System.out.println(k[i++]);

}

// get boolean array

System.out.println(x=re.eval("iris[[1]]>mean(iris[[1]])"));

// R knows about TRUE/FALSE/NA, so we cannot use boolean[] this way

// instead, we use int[] which is more convenient (and what R uses internally anyway)

int[] bi = x.asIntArray();

{

int i = 0; while (i<bi.length) { System.out.print(bi[i]==0?"F ":(bi[i]==1?"T ":"NA ")); i++; }

System.out.println("");

}

// push a boolean array

boolean by[] = { true, false, false };

re.assign("bool", by);

System.out.println(x=re.eval("bool"));

// asBool returns the first element of the array as RBool

// (mostly useful for boolean arrays of the length 1). is should return true

System.out.println("isTRUE? "+x.asBool().isTRUE());

// now for a real dotted-pair list:

System.out.println(x=re.eval("pairlist(a=1,b='foo',c=1:5)"));

RList l = x.asList();

if (l!=null) {

int i=0;

String [] a = l.keys();

System.out.println("Keys:");

while (i<a.length) System.out.println(a[i++]);

System.out.println("Contents:");

i=0;

while (i<a.length) System.out.println(l.at(i++));

}

System.out.println(re.eval("sqrt(36)"));

} catch (Exception e) {

System.out.println("EX:"+e);

e.printStackTrace();

}

// Part 2 - low-level API - for illustration purposes only!

//System.exit(0);

// simple assignment like a<-"hello" (env=0 means use R_GlobalEnv)

long xp1 = re.rniPutString("hello");

re.rniAssign("a", xp1, 0);

// Example: how to create a named list or data.frame

double da[] = {1.2, 2.3, 4.5};

double db[] = {1.4, 2.6, 4.2};

long xp3 = re.rniPutDoubleArray(da);

long xp4 = re.rniPutDoubleArray(db);

// now build a list (generic vector is how that's called in R)

long la[] = {xp3, xp4};

long xp5 = re.rniPutVector(la);

// now let's add names

String sa[] = {"a","b"};

long xp2 = re.rniPutStringArray(sa);

re.rniSetAttr(xp5, "names", xp2);

// ok, we have a proper list now

// we could use assign and then eval "b<-data.frame(b)", but for now let's build it by hand:

String rn[] = {"1", "2", "3"};

long xp7 = re.rniPutStringArray(rn);

re.rniSetAttr(xp5, "row.names", xp7);

long xp6 = re.rniPutString("data.frame");

re.rniSetAttr(xp5, "class", xp6);

// assign the whole thing to the "b" variable

re.rniAssign("b", xp5, 0);

{

System.out.println("Parsing");

long e=re.rniParse("data(iris)", 1);

System.out.println("Result = "+e+", running eval");

long r=re.rniEval(e, 0);

System.out.println("Result = "+r+", building REXP");

REXP x=new REXP(re, r);

System.out.println("REXP result = "+x);

}

{

System.out.println("Parsing");

long e=re.rniParse("iris", 1);

System.out.println("Result = "+e+", running eval");

long r=re.rniEval(e, 0);

System.out.println("Result = "+r+", building REXP");

REXP x=new REXP(re, r);

System.out.println("REXP result = "+x);

}

{

System.out.println("Parsing");

long e=re.rniParse("names(iris)", 1);

System.out.println("Result = "+e+", running eval");

long r=re.rniEval(e, 0);

System.out.println("Result = "+r+", building REXP");

REXP x=new REXP(re, r);

System.out.println("REXP result = "+x);

String s[]=x.asStringArray();

if (s!=null) {

int i=0; while (i<s.length) { System.out.println("["+i+"] \""+s[i]+"\""); i++; }

}

}

{

System.out.println("Parsing");

long e=re.rniParse("rnorm(10)", 1);

System.out.println("Result = "+e+", running eval");

long r=re.rniEval(e, 0);

System.out.println("Result = "+r+", building REXP");

REXP x=new REXP(re, r);

System.out.println("REXP result = "+x);

double d[]=x.asDoubleArray();

if (d!=null) {

int i=0; while (i<d.length) { System.out.print(((i==0)?"":", ")+d[i]); i++; }

System.out.println("");

}

System.out.println("");

}

{

REXP x=re.eval("1:10");

System.out.println("REXP result = "+x);

int d[]=x.asIntArray();

if (d!=null) {

int i=0; while (i<d.length) { System.out.print(((i==0)?"":", ")+d[i]); i++; }

System.out.println("");

}

}

re.eval("print(1:10/3)");

if (true) {

// so far we used R as a computational slave without REPL

// now we start the loop, so the user can use the console

System.out.println("Now the console is yours ... have fun");

re.startMainLoop();

} else {

re.end();

System.out.println("end");

}

}