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List:       r-devel
Subject:    Re: [Rd] Producing different text formats in R
From:       <Lluis.Hurtado () uv ! es>
Date:       2019-08-09 10:30:02
Message-ID: 4476463122hurgil () uv ! es
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Thank you for your fast answer. It just works fine now.

And apologies for attaching heavy files.

Lluís.

> > > > > > "Lluís" ==   <Lluis.Hurtado@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
> 

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