spplot [SEC=UNCLASSIFIED]

Thank you, Edzer.
My second question bas been solved by using:
proj4string(pred.mud.ked) <- CRS("+proj=longlat +datum=WGS84")

For the first question, I have checked ?levelplot, but found no clue to do what I intended. Thanks for any further help.
  

Cheers,
Jin


-----Original Message-----
From: Edzer Pebesma [mailto:edzer.pebesma at uni-muenster.de]
Sent: Thursday, 23 April 2009 4:08 PM
To: Li Jin
Cc: Roger.Bivand at nhh.no; r-sig-geo at stat.math.ethz.ch
Subject: Re: [R-sig-Geo] spplot [SEC=UNCLASSIFIED]

Dear Jin, the

  ..., scales=list(draw=T), ...

only prints the degree E and degree S on the axis tic marks when it is convinced the data are in long lat. Use

  proj4string(pred.mud.ked) <- "+proj=longlat"

maybe with the right datum, to set this for pred.mud.ked; in principle you could set it early on in your analysis and it should propagate. Be aware that interpolation in gstat will do something different when it finds out that data are in degrees, as it can no longer use coordinates "easily" to compute Euclidian distances.

To change the colorkey, read the help of function levelplot in package lattice, in particular argument colorkey.
--
Edzer


Jin.Li at ga.gov.au wrote:
  

Dear Roger and Mike,
Thank you very much for your kind help. Now I have basically achieved what I initially planned. Here is the code used for plotting the attached map.

library(maptools)
pred.mud.ked<-read.table("mud.ked.csv", sep=",", header=TRUE)
par (font.axis=2, font.lab=2)
coordinates(pred.mud.ked) = ~LON+LAT
gridded(pred.mud.ked)<-TRUE
jpeg("mud.n.ked100.2.jpeg", width=670, height=670, quality=100)
trellis.par.set(sp.theme(regions = list(col = colorRampPalette(c("lightyellow", "saddlebrown")))) )
spplot(pred.mud.ked, c("bt.pred"), scales=list(draw=T), xlab=expression("Longitude"^o), ylab=expression("Latitude"^o),
    main = list("Predicted mud distribution in northern Australian EEZ area using KED", cex=1, col="black", font=2))
dev.off()
detach(package:maptools)

Now I have two other questions.
1. Given that the data range is between 0(%) to 100(%), but the scale bar shows a range beyond this data range, how could I make it start from 0(%) to 100(%) and also add unit (i.e. %) to the scale bar?
2. The text adjacent to axes only show a number without degree symbol and E or S, how to add these and make the text adjacent to axes look like http://r-spatial.sourceforge.net/gallery/#fig09.R?
Any help is greatly appreciated.
Cheers,
Jin

-----Original Message-----
From: Roger Bivand [mailto:Roger.Bivand at nhh.no]
Sent: Wednesday, 22 April 2009 4:52 PM
To: Li Jin
Cc: Michael Sumner; r-sig-geo at stat.math.ethz.ch
Subject: Re: [R-sig-Geo] spplot [SEC=UNCLASSIFIED]

On Wed, 22 Apr 2009, Michael Sumner wrote:


    

Ouch - sorry about that, I should have checked.

I don't know how to set axis labels with spplot I'm afraid.

      

Something like:

library(maptools)
xx <- readShapeSpatial(system.file("shapes/sids.shp", package="maptools")[1],
  IDvar="FIPSNO", proj4string=CRS("+proj=longlat +ellps=clrk66"))
spplot(xx, c("BIR74", "BIR79"), scales=list(draw=TRUE))

Hope this helps,

Roger


    

Regards, Mike.


==============Original message text===============
On Wed, 22 Apr 2009 11:49:09 +1000 Jin.Li at ga.gov.au wrote:

Thank you very much, Mike. That is very helpful. I got the colour I was
after. My data are in lat/long, when I tried degAxis I got:

      

degAxis(1)

        

Error in axis(side, at = at, labels = labels, ...) :
 plot.new has not been called yet

      

degAxis(2)

        

Error in axis(side, at = at, labels = labels, ...) :
 plot.new has not been called yet
It seems degAxis is not working with spplot. Any suggestions? Thanks.
Cheers,
Jin


-----Original Message-----
From: Michael Sumner [mailto:mdsumner at utas.edu.au]
Sent: Wednesday, 22 April 2009 11:08
To: Li Jin
Cc: r-sig-geo at stat.math.ethz.ch
Subject: Re: [R-sig-Geo] spplot [SEC=UNCLASSIFIED]

This examples shows the use of colorRampPalette(grDevices) to create a
color ramp with sp.theme, borrowing from the spplot documentation. See
colors()[grep("brown", colors())]
to find the browns R already knows about, or generate your own.

 library(lattice)
    trellis.par.set(sp.theme(regions = list(col =
colorRampPalette(c("sandybrown", "brown4")))) )


    data(meuse.grid)
    gridded(meuse.grid)=~x+y
    meuse.grid$g = factor(sample(letters[1:5], 3103,
replace=TRUE),levels=letters[1:10])
    meuse.grid$f = factor(sample(letters[6:10], 3103,
replace=TRUE),levels=letters[1:10])
    spplot(meuse.grid, c("f","g"))

If your data are already in latitude/longitude then just type this to add
the graticule and labels:

degAxis(1)
degAxis(2)

If your data use a different projection there's an example here that
transforms lines from lat/lon to the grid, but it would be more work to
figure out for your case:

http://geography.uoregon.edu/GeogR/examples/maps_examples02.htmHTH

Regards, Mike.

==============Original message text===============
On Wed, 22 Apr 2009 10:39:21 +1000 Jin.Li at ga.gov.au wrote:

Dear all,

I am using spplot to generate some maps. The maps produced are beautiful
as shown by the attached file, but I was wondering if it is possible to
do the following modifications:
1) change the colour to brown, that is a value 0 corresponding to
blank/white, 100 to brown, values in between to lighter browns, something
like we can get by brown((0:100)/100); this colour is required for mud by
my organisation; and
2) add lat and long on the axes/borders.

Thanks for your help in advance.

Cheers,

Jin

--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no



------------------------------------------------------------------------

------------------------------------------------------------------------

--
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of M?nster
Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de/
http://www.springer.com/978-0-387-78170-9 e.pebesma at wwu.de