R devel - Mar 2015 - R-devel does not update the C++ returned variables

Hi,

Within my R code, I am using a C++ function as below:

     overlaps <- matrix(0, nrow=B, ncol=length(N))
        overlaps.P <- matrix(0, nrow=B, ncol=length(N))

       .C("speedUp", D, S, pD, pS, nrow(D), as.integer(N), length(N),
           ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)


the function "speedUp", is supposed to update matrices overlaps and
 overlaps.P and it works with official R versions.
However, using the same code in R-devel, it does not update matrices and
they remain all zero without returning any errors.
But, if I store the return values from C function in a variable lets say
"test" as follows:

test <-        .C("speedUp", D, S, pD, pS, nrow(D), as.integer(N),
length(N),
           ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)

then the corresponding element of test to matrix "overlaps"
(test[["overlaps"]]) again has the updated values (correct non-zero
values)
though the overlaps matrix itself is still empty.

I mean in official R, the "overlaps" matrix is updated after calling
the
function but not in R-devel. Also it works in both environment and return
correct values to variable "test" in R-devel as well.
Did you face any similar problem so that R-devel does not update the
variable returned by C++?

Thanks for the help.

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On 02/03/2015 3:50 AM, sarah manderni wrote:
> Hi,
> 
> Within my R code, I am using a C++ function as below:
> 
>      overlaps <- matrix(0, nrow=B, ncol=length(N))
>         overlaps.P <- matrix(0, nrow=B, ncol=length(N))
> 
>        .C("speedUp", D, S, pD, pS, nrow(D), as.integer(N),
length(N),
>            ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)
> 
> 
> the function "speedUp", is supposed to update matrices overlaps
and
>  overlaps.P and it works with official R versions.
> However, using the same code in R-devel, it does not update matrices and
> they remain all zero without returning any errors.
See the NEWS:  DUP=FALSE is now ignored.  It led to too many bugs.  Use
the .Call interface if duplication causes problems.

Duncan Murdoch
> But, if I store the return values from C function in a variable lets say
> "test" as follows:
> 
> test <-        .C("speedUp", D, S, pD, pS, nrow(D),
as.integer(N),
> length(N),
>            ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)
> 
> then the corresponding element of test to matrix "overlaps"
> (test[["overlaps"]]) again has the updated values (correct
non-zero values)
> though the overlaps matrix itself is still empty.
> 
> I mean in official R, the "overlaps" matrix is updated after
calling the
> function but not in R-devel. Also it works in both environment and return
> correct values to variable "test" in R-devel as well.
> Did you face any similar problem so that R-devel does not update the
> variable returned by C++?
> 
> Thanks for the help.
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

Thanks! I went through the online posts which supports the power of .Call
over .C. But my probably naive question is why does this work for my code
with R but not R-devel?
And another question is related to using .Call. Based on the manual page, I
do not need to change the function parameters when using .Call. So I can
run like this:
.Call("sppedUp", D, S, pD, pS, nrow(D), as.integer(N), length(N),
           ssq[i], i, as.integer(B), overlaps, overlaps.P)

But I am receiving the memory(?) related error:
terminate called after throwing an instance of 'std::bad_alloc'  
what():
 std::bad_alloc
Now that I am running the code using .Call.

Thanks.

On Mon, Mar 2, 2015 at 2:01 PM, Duncan Murdoch <murdoch.duncan at
gmail.com>
wrote:
> On 02/03/2015 3:50 AM, sarah manderni wrote:
> > Hi,
> >
> > Within my R code, I am using a C++ function as below:
> >
> >      overlaps <- matrix(0, nrow=B, ncol=length(N))
> >         overlaps.P <- matrix(0, nrow=B, ncol=length(N))
> >
> >        .C("speedUp", D, S, pD, pS, nrow(D), as.integer(N),
length(N),
> >            ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)
> >
> >
> > the function "speedUp", is supposed to update matrices
overlaps and
> >  overlaps.P and it works with official R versions.
> > However, using the same code in R-devel, it does not update matrices
and
> > they remain all zero without returning any errors.
>
> See the NEWS:  DUP=FALSE is now ignored.  It led to too many bugs.  Use
> the .Call interface if duplication causes problems.
>
> Duncan Murdoch
>
> > But, if I store the return values from C function in a variable lets
say
> > "test" as follows:
> >
> > test <-        .C("speedUp", D, S, pD, pS, nrow(D),
as.integer(N),
> > length(N),
> >            ssq[i], i, as.integer(B), overlaps, overlaps.P, DUP=FALSE)
> >
> > then the corresponding element of test to matrix "overlaps"
> > (test[["overlaps"]]) again has the updated values (correct
non-zero
> values)
> > though the overlaps matrix itself is still empty.
> >
> > I mean in official R, the "overlaps" matrix is updated after
calling the
> > function but not in R-devel. Also it works in both environment and
return
> > correct values to variable "test" in R-devel as well.
> > Did you face any similar problem so that R-devel does not update the
> > variable returned by C++?
> >
> > Thanks for the help.
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
>
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