R help - May 2009 - Overlaying two plots

Hi useR's,

I want to overlay an image plot over a world map and I can do it, but just
not the way I need to do it.  Here is the code I am using (with data file
attached) to create my baseline map:
library(sp)
load("TM_WORLD_BORDERS_SIMPL-0.2.RData")
par(bty="l")
plot(wrld_simpl, axes = TRUE, ylim = c(-90, 90), xlim=c(-180, 180), asp=1.5)
lim <- par("usr")
abline(v=-180, h=90, col="red")  #Image plot needs to be inside this
square#
abline(v=180, h=-90, col="red")

The last two statements create a square on the map between the latitude and
longitude limits of the world.  I want to place the following image plot
(data matrix attached) inside that square region and then overlay the world
map again.  When I use the following code, the image plot takes up the whole
plot screen and is not within the square region and thus when I overlay the
world map, the coordinates will be off.

df <- as.matrix(read.table("kz_time1.txt", header=F))
dff <- apply(df, 2, rev)
image(t(dff), xlab="", ylab="", axes=FALSE)

par(new=TRUE)
plot(wrld_simpl, axes = TRUE, ylim = c(-90, 90), xlim=c(-180, 180), asp 1.5,
xlab="Longitude", ylab="Latitude")
abline(v=-180, h=90, col="red") 
abline(v=180, h=-90, col="red")

Can anyone help?
Thanks in advance.
dxc13

  http://www.nabble.com/file/p23526662/TM_WORLD_BORDERS_SIMPL-0.2.RData
TM_WORLD_BORDERS_SIMPL-0.2.RData 
http://www.nabble.com/file/p23526662/kz_time1.txt kz_time1.txt 
-- 
View this message in context:
http://www.nabble.com/Overlaying-two-plots-tp23526662p23526662.html
Sent from the R help mailing list archive at Nabble.com.

Try using the subplot function from the TeachingDemos package.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of dxc13
> Sent: Wednesday, May 13, 2009 12:06 PM
> To: r-help at r-project.org
> Subject: [R] Overlaying two plots
> 
> 
> Hi useR's,
> 
> I want to overlay an image plot over a world map and I can do it, but
> just
> not the way I need to do it.  Here is the code I am using (with data
> file
> attached) to create my baseline map:
> library(sp)
> load("TM_WORLD_BORDERS_SIMPL-0.2.RData")
> par(bty="l")
> plot(wrld_simpl, axes = TRUE, ylim = c(-90, 90), xlim=c(-180, 180),
> asp=1.5)
> lim <- par("usr")
> abline(v=-180, h=90, col="red")  #Image plot needs to be inside
this
> square#
> abline(v=180, h=-90, col="red")
> 
> The last two statements create a square on the map between the latitude
> and
> longitude limits of the world.  I want to place the following image
> plot
> (data matrix attached) inside that square region and then overlay the
> world
> map again.  When I use the following code, the image plot takes up the
> whole
> plot screen and is not within the square region and thus when I overlay
> the
> world map, the coordinates will be off.
> 
> df <- as.matrix(read.table("kz_time1.txt", header=F))
> dff <- apply(df, 2, rev)
> image(t(dff), xlab="", ylab="", axes=FALSE)
> 
> par(new=TRUE)
> plot(wrld_simpl, axes = TRUE, ylim = c(-90, 90), xlim=c(-180, 180), asp
> > 1.5, xlab="Longitude", ylab="Latitude")
> abline(v=-180, h=90, col="red")
> abline(v=180, h=-90, col="red")
> 
> Can anyone help?
> Thanks in advance.
> dxc13
> 
>   http://www.nabble.com/file/p23526662/TM_WORLD_BORDERS_SIMPL-0.2.RData
> TM_WORLD_BORDERS_SIMPL-0.2.RData
> http://www.nabble.com/file/p23526662/kz_time1.txt kz_time1.txt
> --
> View this message in context: http://www.nabble.com/Overlaying-two-
> plots-tp23526662p23526662.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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