[Rd] Producing different text formats in R

Liuis@Hurt@do m@iii@g oii uv@es
Fri, 09 Aug 2019 10:30:02 -0000

Thank you for your fast answer. It just works fine now.

And apologies for attaching heavy files.

Llu?s.

> >>>>> "Llu?s" ==   <Lluis.Hurtado at uv.es>
writes:
>
>     Llu?s> Dear all,
>     Llu?s> I am facing a strange problem with text files formats.
>
>     Llu?s> I am currently using a C++ code named voro++
(http://mathlbl.gov/voro++/). This code accepts text files with four columns:
>
>     Llu?s> <id> <x> <y> <z>
>
>     Llu?s> where id is an identification number and x,y,z are the
coordinates of a point in a 3D space.
>
>     Llu?s> The input file, name it myfile_cpp.txt, is generated by
another C++ code written by myself (named quadscheme.cpp). So far, these
calculations involve no R code and it works just fine.
>
>     Llu?s> However, now I am trying to replace my C++ code
quadscheme.cpp by a R function. The four columns (id,x,y,z) are produced in a
matrix or Data Frame and then saved in a file myfile_r.txt using write.table().
For example using the following function:
>
>     Llu?s> quadscheme <- function(window, ntile) {
>     Llu?s>   # Creates a grid of points in a 3D orthohedron.
>     Llu?s>   # First point lies at the (mix,miny,miz) corner of the
volume and the last one at (maxx,maxy,maxz)
>     Llu?s>   # window: vector. Contains the minimum and maximum values
of a 3D orthohedron
>     Llu?s>   #       window <- c(minx, maxx, miny, maxy, minz, maxz)
>     Llu?s>   # ntile: vector. Number of points per dimension minus one.
We manually add a extra row of points per dimension
>     Llu?s>   #       ntile <- c(nstepx, nstepy, nstepz)
>     Llu?s>   M <- prod(ntile+1)
>     Llu?s>   mat <- matrix(NA,M,4)
>     Llu?s>   mat[,1] <- 1:M # id column
>
>     Llu?s>   # step length per dimension
>     Llu?s>   hi <- (window[2] - window[1])/ntile[1]
>     Llu?s>   hj <- (window[4] - window[3])/ntile[2]
>     Llu?s>   hk <- (window[6] - window[5])/ntile[3]
>
>     Llu?s>   c <- 1
>     Llu?s>   for(i in 0:ntile[1]) {
>     Llu?s>     x <- i*hi + window[1]
>     Llu?s>     for(j in 0:ntile[2]) {
>     Llu?s>       y <- hj*j + window[3]
>     Llu?s>       for(k in 0:ntile[3]) {
>     Llu?s>         z <- k*hk + window[5]
>     Llu?s>         mat[c,2:4] <- c(x,y,z) # Add a new point to the
grid
>     Llu?s>         c <- c + 1
>     Llu?s>       }
>     Llu?s>     }
>     Llu?s>   }
>     Llu?s>   write.table(mat, file="myfile_r.txt",
row.names=FALSE, col.names=FALSE)
>     Llu?s> }
>
>     Llu?s> And then calling:
>
>     >> window <- c(18, 43, 171, 196, 95, 102)
>     >> ntile <- c(100,100,28)
>     >> quadscheme(window, ntile)
>
>     Llu?s> I see no difference between both myfile_*.txt files,
>     Llu?s> one is created with C++ and the other one with
>     Llu?s> R. However, function voro++ do not accept the later one
>     Llu?s> (created with R and saved with write.table). I've also
>     Llu?s> noted that voro++ usually accepts R generated files
>     Llu?s> when they are small enough, but it accepts all C++
>     Llu?s> generated files, regardless the size.
>
>     Llu?s> I know this is more a C++ than a R question, but may be
>     Llu?s> you can help me as well. I suspect that even if both
>     Llu?s> files are *.txt they have some differences that I
>     Llu?s> cannot see. Is there any way in R to produce different
>     Llu?s> kinds of txt files? Like binary instead of text files?
>     Llu?s> Could this be the problem?
>
>     Llu?s> I attach two identical files, one produced by C++
>     Llu?s> (myfile_cpp.txt) and another one by the previous R
>     Llu?s> function (myfile_r.txt). I attach as well the C++ code
>     Llu?s> used to generate myfile_cpp.txt.
>
>     Llu?s> Thank you in advance,
>
>     Llu?s> Llu?s Hurtado-Gil
>
> In your R file, scientific notation is used:
>
> R:
>   99999 26.5 174.5 96.5
>   1e+05 26.5 174.5 96.75
>   100001 26.5 174.5 97
>
> cpp:
>   99999 26.5 174.5 96.5
>   100000 26.5 174.5 96.75
>   100001 26.5 174.5 97
>
> Try setting options(scipen = 20) before you write the
> file in R.
>
>
>
> --
> Enrico Schumann
> Lucerne, Switzerland
> http://enricoschumann.net
>