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plot() and Jpeg() increase font size and resolution

3 messages · Alexander.Herr at csiro.au, Edzer Pebesma, Roger Bivand

Original
Alexander.Herr at csiro.au
# 
Dear list,

I am having troubles increasing the fontize when plotting a
variogram{gstat} and its model (vgm) with plot and using jpeg(). Also
the resolution in the jpeg call does not work. I am using R2.4 on
Mandriva 10.2 linux.

I can change fontsize with cex.axis in a normal plot, so I presume it
has to do with plotting the variogram model. Any help on how to increase
the font size and resolution would be appreciated?

R-calls:
v1<-variogram(log(z)~x+y, loc=coordinates(shp1),data=shp1)
m1<-vgm(0.0175, "Gau", 200000,0.052)

jpeg(file="LOTPLAN_variogram_mod.jpg", bg="white", res=300,
pointsize=16, width=1200, height=1200, quality=100)

 plot(v1,plot.number=F, model=m1, ylim=c(0.04,0.08), col="black",
cex.axis=1.5)

dev.off()

Thanks Herry

Dr Alexander Herr
Spatial and statistical analyst
CSIRO, Sustainable Ecosystems
Davies Laboratory,
University Drive, Douglas, QLD 4814 
Private Mail Bag, Aitkenvale, QLD 4814
 
Phone/www 
(07) 4753 8510; 4753 8650(fax)
Home: http://herry.ausbats.org.au
Webadmin ABS: http://ausbats.org.au
Sustainable Ecosystems: http://www.cse.csiro.au/
Edzer Pebesma
# 
plotting variograms in gstat is done through xyplot in lattice; you'll 
find where it gets it's defaults by

library(lattice)
trellis.par.get()
?trellis.par.set
--
Edzer
Alexander.Herr at csiro.au wrote:
Roger Bivand
#
On Fri, 24 Nov 2006 Alexander.Herr at csiro.au wrote:

            

      
      
      
    

        
I believe that the underlying plot.gstatVariogram() method uses lattice 
graphics, not base graphics. So the problem is to find the right way of 
passing the parameter for xyplot(), and then see if plot.gstatVariogram() 
lets you do the same.

df <- data.frame(x=1:10, y=runif(10))
xyplot(y ~ x, df, scales=list(cex=3))

works, but

data(meuse)
vgm1 <- variogram(log(zinc)~1, ~x+y, meuse)
plot(vgm1, scales=list(cex=3))

unfortunately doesn't, so more exploration will be needed. I think the 
scales= argument is not passed through in the final brach to xyplot() in 
gstat:::plot.gstatVariogram(). From the examples:

plot(v, group.id = FALSE, auto.key = TRUE, scales=list(cex=2))

works, but

plot(vgm2, scales=list(cex=2))

doesn't.

Roger