Bare test code: My simple Java test class source and R test code follow: public class RJavTest { public static void main(String[]args) { RJavTest rJavTest=new RJavTest(); } public final static String conStg="testString"; public final static double con0dbl=10000001; public final static double[]con1Arr=new double[] { 10001,10002,10003,10004,10005,10006 }; public final static double[][]con2Arr=new double[][] { { 101,102,103,104 },{ 201,202,203,204 },{ 301,302,303,304 } }; public final static String retConStg() { return(conStg); } public final static double retCon0dbl() { return(con0dbl); } public final static double[] retCon1Arr() { return(con1Arr); } public final static double[][] retCon2Arr() { return(con2Arr); } } library(rJava) .jinit() .jaddClassPath("C:/ad/j") # a directory on my disk print(.jclassPath()) rJavaTst <- .jnew("RJavTest") # compilation of class code connStg <- .jfield(rJavaTst,sig="S","conStg") print(connStg) connStgRet <- .jcall(rJavaTst,returnSig="S","retConStg") print(connStgRet) conn1Arr <- .jfield(rJavaTst,sig="[D","con1Arr") print(conn1Arr) print(conn1Arr[2]) conn1ArrRet <- .jcall(rJavaTst,returnSig="[D","retCon1Arr") print(conn1ArrRet) print(conn1ArrRet[2]) conn0dbl <- .jfield(rJavaTst,sig="D","con0dbl") print(conn0dbl,digits=15) # The above is just for education, question on rectangular is below conn2Arr <- .jfield(rJavaTst,sig="[[D","con2Arr") conn2ArrRet <- .jcall(rJavaTst,returnSig="[[D","retCon2Arr") # I can't identify any complaints so far print(conn2Arr) print(conn2ArrRet) The results are:> library(rJava) > .jinit() > .jaddClassPath("C:/ad/j") # a directory on my disk > print(.jclassPath())[1] "C:\\Users\\ENVY17\\Documents\\R\\win-library\\2.12\\rJava\\java" [2] "C:\\ad\\j"> rJavaTst <- .jnew("RJavTest") # compilation of class code > connStg <- .jfield(rJavaTst,sig="S","conStg") > print(connStg)[1] "testString"> connStgRet <- .jcall(rJavaTst,returnSig="S","retConStg") > print(connStgRet)[1] "testString"> conn1Arr <- .jfield(rJavaTst,sig="[D","con1Arr") > print(conn1Arr)[1] 10001 10002 10003 10004 10005 10006> print(conn1Arr[2])[1] 10002> conn1ArrRet <- .jcall(rJavaTst,returnSig="[D","retCon1Arr") > print(conn1ArrRet)[1] 10001 10002 10003 10004 10005 10006> print(conn1ArrRet[2])[1] 10002> conn0dbl <- .jfield(rJavaTst,sig="D","con0dbl") > print(conn0dbl,digits=15)[1] 10000001> # The above is just for education, question on rectangular is below > conn2Arr <- .jfield(rJavaTst,sig="[[D","con2Arr") > conn2ArrRet <- .jcall(rJavaTst,returnSig="[[D","retCon2Arr") > # I can't identify any complaints so far > print(conn2Arr)[[1]] [1] "Java-Array-Object[D:[D at 66848c" [[2]] [1] "Java-Array-Object[D:[D at 8813f2" [[3]] [1] "Java-Array-Object[D:[D at 1d58aae"> print(conn2ArrRet)[[1]] [1] "Java-Array-Object[D:[D at 66848c" [[2]] [1] "Java-Array-Object[D:[D at 8813f2" [[3]] [1] "Java-Array-Object[D:[D at 1d58aae">But what meaning should get from these strange messages? -- View this message in context: http://r.789695.n4.nabble.com/Copying-to-R-a-rectangular-array-from-a-Java-class-tp3486167p3486167.html Sent from the R help mailing list archive at Nabble.com.
I discovered that a row of a rectangular array returns, but a function parameter is not sent to Java. Appended bare test code: My simple Java test class source and R test code follow: public class RJavTest { public static void main(String[]args) { RJavTest rJavTest=new RJavTest(); } public final static String conStg="testString"; public final static double con0dbl=10000001; public final static double[]con1Arr=new double[] { 10001,10002,10003,10004,10005,10006 }; public final static double[][]con2Arr=new double[][] { { 101,102,103,104 },{ 201,202,203,204 },{ 301,302,303,304 } }; public final static String retConStg() { return(conStg); } public final static double retCon0dbl() { return(con0dbl); } public final static double[] retCon1Arr() { return(con1Arr); } public final static double[] retCon2Row0() { return(con2Arr[0]); } public final static double[] retCon2Row(int row) { return(con2Arr[row]); } public final static double[][] retCon2Arr() { return(con2Arr); } } library(rJava) .jinit() .jaddClassPath("C:/ad/j") # a directory on my disk print(.jclassPath()) rJavaTst <- .jnew("RJavTest") # compiled java to class file connStg <- .jfield(rJavaTst,sig="S","conStg") print(connStg) connStgRet <- .jcall(rJavaTst,returnSig="S","retConStg") print(connStgRet) conn1Arr <- .jfield(rJavaTst,sig="[D","con1Arr") print(conn1Arr) print(conn1Arr[2]) conn1ArrRet <- .jcall(rJavaTst,returnSig="[D","retCon1Arr") print(conn1ArrRet) print(conn1ArrRet[2]) conn0dbl <- .jfield(rJavaTst,sig="D","con0dbl") print(conn0dbl,digits=15) conn2Row0Ret <- .jcall(rJavaTst,returnSig="[D","retCon2Row0") print(conn2Row0Ret) print(conn2Row0Ret[2]) # The above is education, questions on rectangular and parameters are below conn2Arr <- .jfield(rJavaTst,sig="[[D","con2Arr") conn2ArrRet <- .jcall(rJavaTst,returnSig="[[D","retCon2Arr") # I can't identify any complaints so far print(conn2Arr) print(conn2ArrRet) conn2RowRet <- .jcall(rJavaTst,returnSig="[D","retCon2Row",0) print(conn2RowRet) print(conn2RowRet[2]) # But what meaning should I get from these strange messages? The results are:> library(rJava) > .jinit() > .jaddClassPath("C:/ad/j") # a directory on my disk > print(.jclassPath())[1] "C:\\Users\\ENVY17\\Documents\\R\\win-library\\2.12\\rJava\\java" [2] "C:\\ad\\j"> rJavaTst <- .jnew("RJavTest") # compiled java to class file > connStg <- .jfield(rJavaTst,sig="S","conStg") > print(connStg)[1] "testString"> connStgRet <- .jcall(rJavaTst,returnSig="S","retConStg") > print(connStgRet)[1] "testString"> conn1Arr <- .jfield(rJavaTst,sig="[D","con1Arr") > print(conn1Arr)[1] 10001 10002 10003 10004 10005 10006> print(conn1Arr[2])[1] 10002> conn1ArrRet <- .jcall(rJavaTst,returnSig="[D","retCon1Arr") > print(conn1ArrRet)[1] 10001 10002 10003 10004 10005 10006> print(conn1ArrRet[2])[1] 10002> conn0dbl <- .jfield(rJavaTst,sig="D","con0dbl") > print(conn0dbl,digits=15)[1] 10000001> conn2Row0Ret <- .jcall(rJavaTst,returnSig="[D","retCon2Row0") > print(conn2Row0Ret)[1] 101 102 103 104> print(conn2Row0Ret[2])[1] 102> # The above is education, questions on rectangular and parameters are > below > conn2Arr <- .jfield(rJavaTst,sig="[[D","con2Arr") > conn2ArrRet <- .jcall(rJavaTst,returnSig="[[D","retCon2Arr") > # I can't identify any complaints so far > print(conn2Arr)[[1]] [1] "Java-Array-Object[D:[D at 66848c" [[2]] [1] "Java-Array-Object[D:[D at 8813f2" [[3]] [1] "Java-Array-Object[D:[D at 1d58aae"> print(conn2ArrRet)[[1]] [1] "Java-Array-Object[D:[D at 66848c" [[2]] [1] "Java-Array-Object[D:[D at 8813f2" [[3]] [1] "Java-Array-Object[D:[D at 1d58aae"> conn2RowRet <- .jcall(rJavaTst,returnSig="[D","retCon2Row",0)Error in .jcall(rJavaTst, returnSig = "[D", "retCon2Row", 0) : method retCon2Row with signature (D)[D not found> print(conn2RowRet)Error in print(conn2RowRet) : object 'conn2RowRet' not found> print(conn2RowRet[2])Error in print(conn2RowRet[2]) : object 'conn2RowRet' not found> # But what meaning should I get from these strange messages? >-- View this message in context: http://r.789695.n4.nabble.com/Copying-to-R-a-rectangular-array-from-a-Java-class-tp3486167p3489899.html Sent from the R help mailing list archive at Nabble.com.
I am happy to report that the author and maintainer of rJava informed me that the 2-dim array in java needs sapply and .jevalArray as follows:> conn2Arr <- sapply(.jfield(rJavaTst,sig="[[D","con2Arr"),.jevalArray) > conn2ArrRet <- > sapply(.jcall(rJavaTst,returnSig="[[D","retCon2Arr"),.jevalArray) > # I can't identify any complaints so far > print(conn2Arr)[,1] [,2] [,3] [1,] 101 201 301 [2,] 102 202 302 [3,] 103 203 303 [4,] 104 204 304> print(conn2ArrRet)[,1] [,2] [,3] [1,] 101 201 301 [2,] 102 202 302 [3,] 103 203 303 [4,] 104 204 304 I know there are a few out there interested since I see I got a few views. But, I don't know the solution to the parameter-passing problem yet. -- View this message in context: http://r.789695.n4.nabble.com/Copying-to-R-a-rectangular-array-from-a-Java-class-tp3486167p3490919.html Sent from the R help mailing list archive at Nabble.com.
Hi, can you please tel me how to retrieve String two dimensional array as like sapply? -- View this message in context: http://r.789695.n4.nabble.com/Copying-to-R-a-rectangular-array-from-a-Java-class-tp3486167p3643223.html Sent from the R help mailing list archive at Nabble.com.