Dear R developers, I spotted that R_isNA and R_IsNaN could be improved when applied on a vector where we could take out small part of their logic, run it once, and then reuse inside the loop. I setup tiny plain-C experiment. Taking R_IsNA, R_IsNaN from R's arithmetic.c, and building R_vIsNA and R_vIsNaN accordingly. For double input of size 1e9 (having some NA and NaN) I observed following timings:
R_IsNA 6.729s R_vIsNA 4.386s R_IsNaN 6.874s R_vIsNaN 4.479s ISNAN 4.392s It looks like R_vIsN(A|aN) are close to ISNAN (which just wraps to math.h::isnan). Should I follow up with a patch? The experiment is a single nan.c file of 127 lines (includes R C funs). Large enough to not paste in the email. Here is the link: https://gist.github.com/jangorecki/c140fed3a3672620c1e2af90a768d785 Run it as: gcc nan.c -lm ./a.out R_vIsNA 8 ./a.out R_IsNA 8 ./a.out R_vIsNaN 8 ./a.out R_IsNaN 8 ./a.out ISNAN 8 Best regards, Jan Gorecki ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
