Thanks Icn for pointing that out, but I don't understand it. My use of .jcall to return a type double scalar or String worked. My use of .jfield to get a one dimensional static array worked. My use of .jfield to get a static scalar constant did not work. My use of .jfield to get a two dimensional static constant array did not work. I don't understand the remainder of my rjava trial.
The C:/ad/j/CalqsLin java code is: public final static double con0dbl=10001; public final static double[]con1Arr=new double[] { 10001,10002,10003,10004,10005,10006 }; public final static double[][]con2Arr=new double[][] { { 10001,10002,10003,10004 },{ 20001,20002,20003,20004 },{ 30001,30002,30003,30004 } }; public final static double[][] arReturnTEST() { double[][]retArr=new double[3][4]; for(int i=0;i<3;i++)for(int j=0;j<4;j++)retArr[i][j]=i*1000+j; return(retArr); } I have the RGui with R Console on the screen; here is the trial: On the top pullDowns: Packages > Install Packages > USA(IA)> rJava > library(rJava) > .jinit() [1] 0 > .jaddClassPath("C:/ad/j") > print(.jclassPath()) [1] "C:\\Users\\ENVY17\\Documents\\R\\win-library\\2.12\\rJava\\java" [2] "C:\\ad\\j" > qsLin <- .jnew("CalqsLin") > calStg <- "201104242359599999" > print(calStg) [1] "201104242359599999" > dblTim <- > .jcall(qsLin,returnSig="D","linTimOfCalqsStgIsLev",calStg,as.integer(-4)) > print(dblTim,digits=20) [1] 634709087999999 > calStg <- > .jcall(qsLin,returnSig="S","calqsStgOfLinTimIsLev",dblTim,as.integer(-4)) > print(calStg) [1] "201104242359599999" > conn1Arr <- .jfield(qsLin,sig="[D","con1Arr") > print(conn1Arr) [1] 10001 10002 10003 10004 10005 10006 > conn0dbl <- .jfield(qsLin,sig="D","con0dbl") Error in .jfield(qsLin, sig = "D", "con0dbl") : RgetField: field con0dbl not found > arj34Ret <- .jcall(qsLin,returnSig="[[D","arReturnTEST") > print(arj34Ret[2][3],digits=15) [[1]] NULL > print(arj34Ret,digits=15) [[1]] [1] "Java-Array-Object[D:[D@1d58aae" [[2]] [1] "Java-Array-Object[D:[D@83cc67" [[3]] [1] "Java-Array-Object[D:[D@e09713" > ar34Ret <- .jevalArray(arj34Ret) Error in .jevalArray(arj34Ret) : object is not a Java object reference (jobjRef/jarrayRef). > print(ar34Ret[2][3],digits=15) Error in print(ar34Ret[2][3], digits = 15) : object 'ar34Ret' not found > print(ar34Ret,digits=20) Error in print(ar34Ret, digits = 20) : object 'ar34Ret' not found > -- View this message in context: http://r.789695.n4.nabble.com/Using-Java-methods-in-R-tp3469299p3476371.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.