[Rcpp-devel] Rcpp speed

[Dirk Eddelbuettel]

Romain rightly scolds me once again for me having forgotten about the fact
that INTSXP != REALSXP, and conversion to NumericVector has a cost.  So once
we keep everything in int, there is no difference:

R> x <- 1L:10L
R> benchmark(replications = 10000,
+           R = x + x, Rfun = funR(x, x), Rcpp = funRcpp(x, x))
  test replications elapsed relative user.self sys.self user.child sys.child
1    R        10000   0.041   1.0000      0.04        0          0         0
3 Rcpp        10000   0.054   1.3171      0.05        0          0         0
2 Rfun        10000   0.054   1.3171      0.06        0          0         0
R> x <- 1L:1000L
R> benchmark(replications=1000, R = x + x, Rfun = funR(x, x), Rcpp = funRcpp(x, x))
  test replications elapsed relative user.self sys.self user.child sys.child
1    R         1000   0.008   1.3333      0.01        0          0         0
3 Rcpp         1000   0.006   1.0000      0.01        0          0         0
2 Rfun         1000   0.009   1.5000      0.01        0          0         0
R> x <- 1L:1000000L
R> benchmark(replications=100, R = x + x, Rfun = funR(x, x), Rcpp = funRcpp(x, x))
  test replications elapsed relative user.self sys.self user.child sys.child
1    R          100   0.436   1.5034      0.43     0.00          0         0
3 Rcpp          100   0.290   1.0000      0.18     0.11          0         0
2 Rfun          100   0.461   1.5897      0.44     0.01          0         0
R> 


Happier now?

Dirk

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com