Adding text to rasterVis levelplot

Ah, I forgot to include the definition of text vectors which must be
inserted before the for() loop - sorry for that.

---
## labels
cls <- c("col1", "col2")
rws <- c("row1", "row2")
---


-------- Forwarded Message --------
Subject:        Re: [R-sig-Geo] Adding text to rasterVis levelplot
Date:   Fri, 21 Jul 2017 10:05:08 +0200
From:   Florian Detsch <florian.detsch at staff.Uni-Marburg.DE>
To:     r-sig-geo at r-project.org



Hi Mauricio,

Complementing Thiago's answer using 'names.att', here is a more manual
approach which might come in handy when a finer control over text
annotations is required. It is built upon lattice::trellis.focus() which
lets you select relevant panels of your trellis graph in an iterative
manner.

---
p <- levelplot(s, layout = c(2, 2), names.att = rep("", 4),
                scales = list(y = list(rot = 90)))

library(grid)

png("~/rasterVis.png", width = 14, height = 16, units = "cm", res = 300L)
grid.newpage()
print(p, newpage = FALSE)

## loop over panels to be labelled (ie 1:3)
panels <- trellis.currentLayout()
for (i in 1:3) {

   # focus on current panel of interest and disable clipping
   ids <- which(panels == i, arr.ind = TRUE)
   trellis.focus("panel", ids[2], ids[1], clip.off = TRUE)

   # add labels
   if (i %in% c(1, 3)) {
     if (i == 1) {
       grid.text(cls[1], x = .5, y = 1.1) # add 'col1'
       grid.text(rws[1], x = -.35, y = .5, rot = 90) # add 'row1'
     } else {
       grid.text(rws[2], x = -.35, y = .5, rot = 90) # add 'row2'
     }
   } else {
     grid.text(cls[2], x = .5, y = 1.1) # add 'col2'
   }

   trellis.unfocus()
}

dev.off()
---

A very similar use case, from which the above approach definitely took
some inspiration, can be found here:
https://stackoverflow.com/questions/7649737/is-it-possible-to-update-a-lattice-panel-in-r.
Have a look at ?grid.text() and ?gpar() to learn more about
customization options.

Cheers,
Florian

--
Dr. Florian Detsch
Environmental Informatics
Department of Geography
Philipps-Universit?t Marburg
Deutschhausstra?e 12
35032 (parcel post: 35037) Marburg, Germany

Phone: +49 (0) 6421 28-25323
Web: http://www.uni-marburg.de/fb19/fachgebiete/umweltinformatik/detschf/index.html


On 20.07.2017 05:07, Thiago V. dos Santos via R-sig-Geo wrote:

You can manually define the names that you want and pass them as arguments to 'names.attr' (the name of each panel) and 'ylab' (the title of the y axis).
Following your example:
col.titles = c('col1','col2','','')
row.titles = c('row1','row2')

levelplot(s, layout=c(2,2),
           names.attr=col.titles,
           ylab=row.titles)

HTH,
Greetings, -- Thiago V. dos Santos
PhD studentLand and Atmospheric ScienceUniversity of Minnesota


On Wednesday, July 19, 2017, 11:13:31 AM CDT, Mauricio Zambrano Bigiarini <mauricio.zambrano at ufrontera.cl> wrote:

Dear all,

I would like to add custom text labels for the columns and rows of a
levelplot object created with he rasterVis package, similar to the
c("Fall", "Winter", "Spring", Summer") used to label the rows and the
c("a",..., "h") used to label the columns in the plot shown int he
following link:

https://stackoverflow.com/questions/43007241/how-to-add-text-to-a-specific-fixed-location-in-rastervis-levelplot

In particular, how can I add c("col1", "col2") and c("row1", "row2")
as column and row headers, respectively, to the following example
plot:

--------- START--------
library(rasterVis)
f <- system.file("external/test.grd", package="raster")
r <- raster(f)
s <- stack(r, r+500, r-500, r+200)
levelplot(s, layout=c(2,2), names.att=rep("",4))
--------- END--------


Thanks in advance for your help,


Mauricio Zambrano-Bigiarini, PhD

=====================================
Department of Civil Engineering
Faculty of Engineering and Sciences
Universidad de La Frontera, Temuco, Chile
=====================================
"The ultimate inspiration is the deadline"
(Nolan Bushnell)
=====================================
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