R help - Oct 2006 - Can I avoid loops here ?

Hi,
      I have two lists of matrices, and I  would like to get  a list of term by
term product, say,
 mylist1<- list( X1,X2);  mylist2<-list(Y1,Y2)

Need: mylist3<-list(X1%*%Y1,X2%*%Y2)

Is there a way that allows me to do this without loops ?

Thanks a lot. 

best

Try:

mapply("%*%", mylist1, mylist2, SIMPLIFY = FALSE)

Please provide self-contained examples as requested on
the last line of every message to r-help.  That means the
data for X1, X2, Y1, Y2 should be included so one can
run the code you post.

On 10/1/06, Tong Wang <wangtong at usc.edu> wrote:
> Hi,
>      I have two lists of matrices, and I  would like to get  a list of term
by term product, say,
>  mylist1<- list( X1,X2);  mylist2<-list(Y1,Y2)
>
> Need: mylist3<-list(X1%*%Y1,X2%*%Y2)
>
> Is there a way that allows me to do this without loops ?
>
> Thanks a lot.
>
> best
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

Thanks Gabor,  I will be more specific next time.

best

----- Original Message -----
From: Gabor Grothendieck <ggrothendieck at gmail.com>
Date: Saturday, September 30, 2006 10:38 pm
Subject: Re: [R] Can I avoid loops here ?
To: Tong Wang <wangtong at usc.edu>
Cc: R help <r-help at stat.math.ethz.ch>
> Try:
> 
> mapply("%*%", mylist1, mylist2, SIMPLIFY = FALSE)
> 
> Please provide self-contained examples as requested on
> the last line of every message to r-help.  That means the
> data for X1, X2, Y1, Y2 should be included so one can
> run the code you post.
> 
> On 10/1/06, Tong Wang <wangtong at usc.edu> wrote:
> > Hi,
> >      I have two lists of matrices, and I  would like to get  a 
> list of term by term product, say,
> >  mylist1<- list( X1,X2);  mylist2<-list(Y1,Y2)
> >
> > Need: mylist3<-list(X1%*%Y1,X2%*%Y2)
> >
> > Is there a way that allows me to do this without loops ?
> >
> > Thanks a lot.
> >
> > best
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html> and provide commented, minimal, self-contained, 
> reproducible code.
> >
>