[R-sig-Geo] How to draw a legend when plotting sf (simple feature) objects

[Manuel Spínola]

Thank you very much Edzer,

it works for me:

> ggplot(nc) + geom_sf(aes(fill = SID79))
Warning message:
st_crs<- : replacing crs does not reproject data; use st_transform for that

2017-02-26 11:46 GMT-06:00 Edzer Pebesma <edzer.pebesma at uni-muenster.de>:

>
>
> On 26/02/17 13:23, Manuel Spínola wrote:
> > Dear list members,
> >
> > How can I draw a legend when plotting an sf (simple feature) object.
> >
> > nc = st_read(system.file("gpkg/nc.gpkg", package="sf"), quiet = TRUE)
> >
> > plot(nc["SID79"])
> >
>
> You're in base plot, so at this moment you can add elements
> incrementally to the plot, see e.g. ?legend.
>
> I have no plans of making this easy or automatic, because I don't think
> that base plot is the right place for it (although packages raster,
> spatstat and fields try hard), but would happily consider contributions.
>
> geom_sf in ggplot2 (now in sf branch on github) will follow up
> sp::spplot for sf objects; see e.g.
>
> https://github.com/edzer/sfr/issues/88#issuecomment-276738460
>
> nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet =
> TRUE)
> ggplot(nc) + geom_sf(aes(fill = SID79))
>
> Trying this with the gpkg you read in above fails for me; it looks like
> ggplot now wrongly assumes that geometry columns are always called
> `geometry' (despite the docs), which is not the case.
> --
> Edzer Pebesma
> Institute for Geoinformatics  (ifgi),  University of Münster
> Heisenbergstraße 2, 48149 Münster, Germany; +49 251 83 33081
> Journal of Statistical Software:   http://www.jstatsoft.org/
> Computers & Geosciences:   http://elsevier.com/locate/cageo/
>
>
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>



-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
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