On 28 February 2024 at 19:05, Avraham Adler wrote: | I am hoping the solution to this question is simple, but I have not | been able to find one. I am building a routine in C to be called from | R. I am including Rmath.h. However, when I have a call to "log", I get | the error "called object 'log' is not a function or a function | pointer. When I "trick" it by calling log1p(x - 1), which I *know* is | exported from Rmath.h, it works. | | More completely, my includes are: | #include <R.h> | #include <Rmath.h> | #include <Rinternals.h> | #include <Rconfig.h> | #include <stdlib.h> // for NULL | #include <R_ext/Rdynload.h> | | The object being logged is a double, passed into C as an SEXP, call it | "a", which for now will always be a singleton. I initialize a pointer | double *pa = REAL(a). I eventually call log(pa[0]), which does not | compile and throws the error listed above. Switching the call to | log1p(pa[0] - 1.0) works and returns the proper answer. | | Even including math.h explicitly does not help, which makes sense as | it is included by Rmath.h.
Can you show the actual line? Worst case rename your source file to end in .cpp, include <cmath> and call std::log. > Rcpp::cppFunction("double mylog(double x) { return std::log(x); }") > mylog(exp(42)) [1] 42 > Dirk -- dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel