Re: [Rd] loess returns different standard errors for identical models (PR#7956)
Peter Dalgaard <[EMAIL PROTECTED]> writes: > Peter Dalgaard <[EMAIL PROTECTED]> writes: > > > Prof Brian Ripley <[EMAIL PROTECTED]> writes: > > > > > I've seen many similar things in a report from valgrind. But they > > > went away when compiled without optimization: it seems optimization > > > often does a fetch one element off the end of an array when attempting > > > to keep the pipelines full. > > > > > I'd start by re-running the valgrind tests without optimization. > > > > I was going to anyway, but the reported problem did carry all the > > hallmarks of the use of a memory location with random content. > > Still present with "-g" recompile, and a breakpoint in lowesb showed > that the last call had garbage in the "iv" array. The latter turned out to be a red herring. Apparently a gdb bug messed up the "x/50d" command that I was using to inspect the array. The real problem was in other arguments, namely "diagl" and "trl" which are declared double precision, but passed "&zero" where "zero" is declared to be of type "Sint". Now, the 64000$ question is whether it is safe to try and fix it for 2.1.1... -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
[Rd] 1-based arrays and copying vectors
I'm interfacing to C code that uses 1-based indexing on arrays -- it ignores the zeroth element. Thus, input vectors from R must be moved up one, and output arrays must be moved down one. What is the best way to deal with this using R internal code? My current approach is: For an input R vector of length n, allocate a new vector(v) of length n+1 and copy input into v[1] to v[1+n]. Call with new vector. For an output array(a) of length n, allocate a new vector of length n-1 and copy a[1] to a[n] into v[0] to v[n-1]. If this is the best approach, is there an idiom for copying vectors? -Lopaka __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] 1-based arrays and copying vectors
On 6/19/05, Rob Lopaka Lee <[EMAIL PROTECTED]> wrote: > I'm interfacing to C code that uses 1-based indexing on arrays -- it > ignores the zeroth element. Thus, input vectors from R must be moved up > one, and output arrays must be moved down one. > > What is the best way to deal with this using R internal code? If the C code can be relied upon to ignore the zero'th element of the array then write a wrapper that gets the array, say int v[], from R and passes &v[-1] to your C code. That has the effect of shifting all the addresses back by one position. > My current approach is: > > For an input R vector of length n, allocate a new vector(v) of length n+1 > and copy input into v[1] to v[1+n]. Call with new vector. > > For an output array(a) of length n, allocate a new vector of length n-1 > and copy a[1] to a[n] into v[0] to v[n-1]. > > If this is the best approach, is there an idiom for copying vectors? In C you could use the memcpy function or the Memcpy macro defined in . __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
