[R] %in% with matrix of lists

[Neal H. Walfield]

On Sat, 30 Jul 2016 19:28:42 +0200,
Bert Gunter wrote:
> Bottom line: No, I dont see any vectorized way to do this.
> 
> However, the following may offer some slight improvement over your approach.
> 
> 1. Why do you need to store these as arrays, which are merely vectors
> with a "dim" attribute?
> 
> ## convert to vectors (a list is also a vector):
> 
> dim(x) <- NULL; dim(y) <- NULL

I apologize that my example was not minimal.  I have the data stored
in an array for other reasons.

> 2. ... and use mapply() instead of sapply() (not clear to me  *how*
> you mean to use sapply() anyway)

Sorry, I meant (and I'm using) mapply.

> > mapply("%in%",y,x)  ## might be slightly faster to use match() directly
> 
> [1]  TRUE FALSE  TRUE FALSE  ## NOT c(T,F,T,F)

I'm not sure what you mean by NOT here.  You get the same answer as I
do, as far as I can see.


Thanks for your help!

:) Neal