On Wed, May 1, 2019 at 7:45 AM Harvey Smith <harvey13...@gmail.com> wrote:
>
> Inside of the anyNA() function, it will use the legacy any(is.na()) code if
> x is an OBJECT(). If x is a vector of POSIXct, it will be an OBJECT(), but
> it is also TYPEOF(x) == REALSXP. Therefore, it will skip the faster
> ITERATE_BY_REGION, which is typically 5x faster in my testing.
>
> Is the OBJECT() condition really necessary, or could it be moved after the
> switch() for the individual TYPEOF(x) ITERATE_BY_REGION calls?
>
> # script to demonstrate performance difference if x is an OBJECT or not by
> using unclass()
> x.posixct = Sys.time() + 1:1e6
> microbenchmark::microbenchmark(
> any(is.na( x.posixct )),
> anyNA( x.posixct ),
> anyNA( unclass(x.posixct) ),
> unit='ms')
>
>
>
> static Rboolean anyNA(SEXP call, SEXP op, SEXP args, SEXP env)
> {
> SEXP x = CAR(args);
> SEXPTYPE xT = TYPEOF(x);
> Rboolean isList = (xT == VECSXP || xT == LISTSXP), recursive = FALSE;
>
> if (isList && length(args) > 1) recursive = asLogical(CADR(args));
> *if (OBJECT(x) || (isList && !recursive)) {*
> SEXP e0 = PROTECT(lang2(install("is.na"), x));
> SEXP e = PROTECT(lang2(install("any"), e0));
> SEXP res = PROTECT(eval(e, env));
> int ans = asLogical(res);
> UNPROTECT(3);
> return ans == 1; // so NA answer is false.
> }
>
> R_xlen_t i, n = xlength(x);
> switch (xT) {
> case REALSXP:
> {
> if(REAL_NO_NA(x))
> return FALSE;
> ITERATE_BY_REGION(x, xD, i, nbatch, double, REAL, {
> for (int k = 0; k < nbatch; k++)
> if (ISNAN(xD[k]))
> return TRUE;
> });
> break;
> }
>
I'm interested in this as well, because it causes performance
degradation in xts subsetting:
https://github.com/joshuaulrich/xts/issues/296
Would it be possible to special-case POSIXct, and perhaps other types
defined in base+recommended packages?
Best,
Josh
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com
R/Finance 2019 | www.rinfinance.com
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