Re: [Gretl-devel] foreign R functions and matrix return values

R has 2nd and 3rd what looks as scalars are actually vector of length 1 There are 6 basic types of elements: hex ->logical ->integer->double-> complex->character Instead of error R uses types coercion: c("a",1)  will be c("a","1") The elements coerced to the rightmost type in the chain above Non-numerics looks like the result of types coercion Run to see <R # From help to Matrix::sparseMatrix i <- c(1,3:8); j <- c(2,9,6:10); x <- 7 * (1:7) (A <- sparseMatrix(i, j, x = x))                    ##  8 x 10 "dgCMatrix" summary(A) ## my addition typeof(A) class(A) Am = as.matrix(A) Am class(Am) typeof(Am) R> So A is a S4-class object My idea is coerce such objects to usual matrices and only export usual matrices Am is ready to export . . . . . . . It will take some time I should study Rf_isMatrix() etc. 21 жовтня 2016, 19:53:30, від "Allin Cottrell" < cottrell(a)wfu.edu >: On Fri, 21 Oct 2016, oleg_komashko(a)ukr.net wrote: Only rectangular, do you mean? The matrix Sven constructed (at first) was nominally rectangular (4 x 1), but element [4,1] (represented by "?" when printed) was not a scalar value. Our current test, applied before attempting to build a gretl matrix from the SEXP (call it "res") we get from an R function is, 1) does Rf_isMatrix(res) return non-zero? 2) If so, does Rf_isReal(res) return non-zero? where the second clause is newly added in response to Sven's example. Only if both parts of the test pass do we try to get the data out of the R object, using gretl_matrix_set(m, i, j, REAL(res)[<index>]); Do you think the above is adequate? Or if not, can you suggest a better test? The main goal here is not that we should be able to handle any old object returned by an R function, but that we don't provoke an error in libR that drags gretl down! Allin _______________________________________________ Gretl-devel mailing list Gretl-devel(a)lists.wfu.edu http://lists.wfu.edu/mailman/listinfo/gretl-devel