[R] [lattice] how to overlay a geographical map on a levelplot?

[Pascal Oettli]

Hello,

I think you need to launch the library 'latticeExtra'. I forgot to 
mention it. Sorry.

 > library(latticeExtra)

Regards,
Pascal


Le 21/11/2012 14:29, Tom Roche a écrit :
>
> https://stat.ethz.ch/pipermail/r-sig-geo/2012-November/016757.html
>>> summary: How to overlay a geographical map on each panel in a lattice
>>> (or Trellis), e.g., of levelplot's?
>
> https://stat.ethz.ch/pipermail/r-help/2012-November/329714.html
>> Does [this] match what you are looking for?
>
> Alas, no: unless I'm doing something wrongly, it either throws an error
> or redraws the viewport. (Note I omit map=state: the world map is good
> enough.) Self-contained example follows:
>
> # start example
> library(lattice) # for plotting
> library(maps)    # for ... maps
>
> # Not too many points, for this example
> # -130° to -59.5: (130-59.5)/1.5=47
> # 23.5° to 58.5°: 58.5-23.5     =35
>
> # define longitudes
> west.lon.deg=-130
> #east.lon.deg=-115    # debugging
> east.lon.deg=-59.5
> step.lon.deg=1.5
> lons  <- c(seq(west.lon.deg, east.lon.deg, step.lon.deg))
> n.lon <- length(lons)
>
> # define latitudes
> south.lat.deg=23.5
> #north.lat.deg=30.5    # debugging
> north.lat.deg=58.5
> step.lat.deg=1.0
> lats  <- c(seq(south.lat.deg, north.lat.deg, step.lat.deg))
> n.lat <- length(lats)
>
> # define vertical levels
> bot.lev.mb=1000
> top.lev.mb=50
> n.lev=4
> levs <- c(seq(from=bot.lev.mb, to=top.lev.mb, length.out=n.lev))
>
> # define concentrations
> grid.3d.len <- n.lon * n.lat * n.lev
> concs <- c(1:grid.3d.len)
>
> # define grid
> grid.3d.df <- expand.grid(longitude=lons, latitude=lats, level=levs)
> # add concentrations as data
> data.3d.df <- cbind(grid.3d.df, concentration=concs)
>
> # debugging
> head(data.3d.df)
> tail(data.3d.df)
>
> # create geographical map: thanks, Pascal Oettli
> wld.map <- map('world', plot=FALSE,
>                 xlim=c(west.lon.deg,east.lon.deg),
>                 ylim=c(south.lat.deg,north.lat.deg))
> wld.df <- data.frame(lon=wld.map$x, lat=wld.map$y)
>
> sigdigs=3 # significant digits for lattice strips
>
> # plot "appropriately" for atmospheric data: use
> # * lattice::levelplot
> # * one column, since atmospheric levels stack vertically
>
> # This gets
> #> Error in levelplot(concentration ~ longitude * latitude | level, data = data.3d.df,  :
> #>   non-numeric argument to binary operator
> # levelplot(
> #    concentration ~ longitude * latitude | level,
> #    data=data.3d.df, layout=c(1,n.lev),
> #    levs=as.character(round(data.3d.df[['level']], 1)),
> #    strip=FALSE,
> #    strip.left=strip.custom(
> #      factor.levels= # thanks, David Winsemius
> #        as.character(signif(unique(data.3d.df[['level']]), sigdigs)),
> #      strip.levels=TRUE,
> #      horizontal=TRUE,
> #      strip.names=FALSE,
> #      # gotta shrink strip text size to fit strip width:
> #      # more on that separately
> #      par.strip.text=list(cex=0.5)
> #    )
> # ) + xyplot(lat ~ lon, wld.df,   type='l', lty=1, lwd=1, col='black')
>
> # This throws no error,
> # but merely redraws the entire viewport with the xyplot
> # rather than overdrawing each panel of the levelplot.
> levelplot(
>     concentration ~ longitude * latitude | level,
>     data=data.3d.df, layout=c(1,n.lev),
>     levs=as.character(round(data.3d.df[['level']], 1)),
>     strip=FALSE,
>     strip.left=strip.custom(
>       factor.levels= # thanks, David Winsemius
>         as.character(signif(unique(data.3d.df[['level']]), sigdigs)),
>       strip.levels=TRUE,
>       horizontal=TRUE,
>       strip.names=FALSE,
>       # gotta shrink strip text size to fit strip width:
>       # more on that separately
>       par.strip.text=list(cex=0.5)
>     )
> )
> xyplot(lat ~ lon, wld.df,   type='l', lty=1, lwd=1, col='black')
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>