R devel - Sep 2010 - lapply version with [ subseting - a suggestion

Dear R developers,

Reviewing my code, I have realized that about 80% of the time in the lapply I
need to access the names of the objects inside the loop.

In such cases I iterate over indexes or names:
lapply(names(x), ... [i]), 
lapply(seq_along(x),  ... x[[i]] ... names(x)[i] ), or
for(i in seq_along(x)) ...

which is rather inconvenient.

How about an argument to lapply which would specify the [ or [[ subseting to use
in the splitting of the vector?
Or may be a different set of functions lapply1,
sapply1?

I believe this pattern is rather common for other users as well.

Thanks.
VS.

On Tue, Sep 21, 2010 at 3:55 AM, Vitaly S. <spinuvit.list@gmail.com>
wrote:
>
> Dear R developers,
>
> Reviewing my code, I have realized that about 80% of the time in the lapply
> I
> need to access the names of the objects inside the loop.
>
> In such cases I iterate over indexes or names:
> lapply(names(x), ... [i]),
> lapply(seq_along(x),  ... x[[i]] ... names(x)[i] ), or
> for(i in seq_along(x)) ...
>
> which is rather inconvenient.
>
> How about an argument to lapply which would specify the [ or [[ subseting
> to use
> in the splitting of the vector?
> Or may be a different set of functions lapply1,
> sapply1?
>
>
I'm not sure what you want exactly, but  what about just using mapply over
the names and vector elements?

> I believe this pattern is rather common for other users as well.
>
> Thanks.
> VS.
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
	[[alternative HTML version deleted]]

See ?vapply also

On Tue, Sep 21, 2010 at 7:55 AM, Vitaly S. <spinuvit.list@gmail.com>
wrote:
>
> Dear R developers,
>
> Reviewing my code, I have realized that about 80% of the time in the lapply
> I
> need to access the names of the objects inside the loop.
>
> In such cases I iterate over indexes or names:
> lapply(names(x), ... [i]),
> lapply(seq_along(x),  ... x[[i]] ... names(x)[i] ), or
> for(i in seq_along(x)) ...
>
> which is rather inconvenient.
>
> How about an argument to lapply which would specify the [ or [[ subseting
> to use
> in the splitting of the vector?
> Or may be a different set of functions lapply1,
> sapply1?
>
> I believe this pattern is rather common for other users as well.
>
> Thanks.
> VS.
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]