[R] Line with linearly changing thickness – installation issues

Sun Nov 11 19:29:47 CET 2018

Dear David and Ferri,

Here's a simple implementation using polygon() (as David suggested). It's much less sophisticated than Paul Murrell's -- in particular, the ends of the line are simply vertical (but, with a bit more work, that too could be addressed) -- and uses standard R graphics rather than grid.

tline <- function(x, y, thickness, col="black", unit=0.005){
    # line of varying thickness
    #   x: vector of x coordinates
    #   y: vector of y coordinates
    #   thickness: units of thickness at each set of coordinates
    #   col: line colour
    #   unit: unit of thickness as fraction of vertical axis
    tl <- function(x1, x2, y1, y2, start, end){
        polygon(x=c(x1, x1, x2, x2, x1), 
                y=c(y1 - start*units, y1 + start*units, 
                    y2 + end*units, y2 - end*units, 
                    y1 - start*units),
                col=col, border=col)
    }
    if (length(x) != length(y)) "x and y are of different lengths"
    if (length(x) != length(thickness)) 
        "length of thickness is different from x and y"
    if (length(x) < 2) "x and y are too short"
    usr <- par("usr")
    units <- (usr[4] - usr[3])*unit/2
    for (i in 2:length(x)){
        tl(x[i - 1], x[i], y[i - 1], y[i], thickness[i - 1], thickness[i])
    }
}

# example:

plot(c(-1, 1), c(0, 100), type="n")
tline(seq(-1, 1, by=0.1), y=(seq(1, 9.5, length=21))^2, 
      thickness=seq(1, 20, length=21), col="blue")

I hope this helps,
 John

--------------------------------------
John Fox, Professor Emeritus
McMaster University
Hamilton, Ontario, Canada
Web: socialsciences.mcmaster.ca/jfox/

> -----Original Message-----
> From: R-help [mailto:r-help-bounces using r-project.org] On Behalf Of David
> Winsemius
> Sent: Sunday, November 11, 2018 12:23 PM
> To: r-help using r-project.org
> Subject: Re: [R] Line with linearly changing thickness – installation
> issues
> 
> I would have imagined that drawing a polygon would be the way most
> people would have attempted.
> 
> Regarding Murrell's package:
> 
> I thought the package name was "vwline". My attempt to install was
> unsuccessful>
> 
>  > devtools::install_github("pmur002/vwline")
> Error in utils::download.file(url, path, method = download_method(),
> quiet = quiet,  :
>    cannot open URL
> 'https://api.github.com/repos/pmur002/vwline/contents/DESCRIPTION?ref=ma
> ster'
>  > install.packages("~/vwline-0.2-1.tar.gz", repo=NULL) Installing
> package into ‘/home/david/R/x86_64-pc-linux-gnu-library/3.5.1’
> (as ‘lib’ is unspecified)
> Warning in untar2(tarfile, files, list, exdir, restore_times) :
>    skipping pax global extended headers
> ERROR: cannot extract package from ‘/home/david/vwline-0.2-1.tar.gz’
> Warning in install.packages :
>    installation of package ‘/home/david/vwline-0.2-1.tar.gz’ had non-
> zero exit status
> 
> 
> Furthermore, I do get the same error from attempting to install
> pkg:twine from github.
> 
> -- David
> 
> Doing this from an Rstudio console running R 3.5.1 in Ubuntu 18.04
> 
> On 11/11/18 8:30 AM, Ferri Leberl wrote:
> > Dear All,
> > Thanks to Peter for his hint to the lwline package.
> > As a pitty, I have difficulties to get it installed, as it requires
> https://github.com/Gibbsdavidl/twine which failes for me.
> >
> > install_github("git using github.com:Gibbsdavidl/twine.git")
> >
> > ends with
> >
> > ** building package indices
> > Error in read.table(zfile, header = TRUE, as.is = FALSE) :
> >    more columns than column names
> > ERROR: installing package indices failed
> > * removing ‘/usr/local/lib/R/site-library/twine’
> > Fehler in i.p(...) :
> >    (konvertiert von Warnung) installation of package
> > ‘/tmp/RtmpD3exKe/file730c303b4c3/twine_0.1.tar.gz’ had non-zero exit
> > status
> >
> > I found hints like
> > https://community.rstudio.com/t/lazydata-failed-for-for-package/4196
> > and https://stat.ethz.ch/pipermail/r-help/2011-March/272829.html
> > that boil down to problems within the data subdir of the project – but
> I cannot (and should not) edit the project, can I?
> >
> > Can anybody help me solving the problem?
> > Thank you in advance!
> > Yours, Ferri
> >
> >
> >
> > Gesendet: Sonntag, 11. November 2018 um 15:38 Uhr
> > Von: "Peter Dalgaard" <pdalgd using gmail.com>
> > An: "Ferri Leberl" <ferri.leberl using gmx.at>
> > Cc: r-help using r-project.org
> > Betreff: Re: [R] Line with linearly changing thickness Hmm... I don't
> > recall whether this has been packaged up, but Paul Murrell talked
> about it at useR in Brisbane.
> >
> > https://www.youtube.com/watch?v=L6FawdEA3W0
> >
> > -pd
> >
> >> On 11 Nov 2018, at 11:44 , Ferri Leberl <ferri.leberl using gmx.at> wrote:
> >>
> >>
> >> Dear All,
> >> I want to depict flows: At point x there is an input of a units. at
> point y, b units arrive.
> >> Obviously, the line thicknes can be manipulated with (a constant)
> cex. But I want the thickness to change linearly from ~a in x to ~b in
> y.
> >> Is there an out of the box solution for this?
> >> Thank you in advance!
> >> Yours, Ferri
> >>
> >> ______________________________________________
> >> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> https://stat.ethz.ch/mailman/listinfo/r-help[https://stat.ethz.ch/mai
> >> lman/listinfo/r-help] PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html[http://www.R-project.org/
> >> posting-guide.html] and provide commented, minimal, self-contained,
> >> reproducible code.
> > --
> > Peter Dalgaard, Professor,
> > Center for Statistics, Copenhagen Business School Solbjerg Plads 3,
> > 2000 Frederiksberg, Denmark
> > Phone: (+45)38153501
> > Office: A 4.23
> > Email: pd.mes using cbs.dk Priv: PDalgd using gmail.com
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ______________________________________________
> > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.