[Rd] Producing different text formats in R

[Liuis@Hurt@do m@iii@g oii uv@es]

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

And apologies for attaching heavy files.

Lluís.

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