Spplot: Specifying individual point symbols

Hi,

I have a problem where I would like to have both the colour and the symbol
varying in an spplot plot. Unfortunately, specifying a list of pch values
doesn't seem to work. See the following example

library(sp)
data(meuse)
coordinates(meuse) <- ~x +y
#Lets plot the elevation
spplot(meuse,"elev")
#And now the distance
spplot(meuse,"dist")
#Lets plot the points close to the river with open points
spplot(meuse,"elev",
       colorkey=TRUE,
       pch=ifelse(meuse$dist<0.3,1,16))

What I'm aiming for is to have all the points close to the river open
circles (pch=1), and all the points further from the river to be closed
(pch=16). However, the pch symbols don't seem to be propigating through
into the panel function correctly. The problem seems to arise somewhere the
Fill.call.groups() function, but I can't quite figure out where....

This type of trick is legitimate in lattice, which is where my inspiration
came from eg:

x <- rnorm(1000)
y <- rnorm(1000)
z <- sqrt(x^2 + y^2)
xyplot(y~x,pch=ifelse(z<1,16,1),asp="iso",cex=1)

As you can see, I have managed to change the symbol according  to the
distance from the centre.

Am I asking too much of spplot to try and achieve this type of thing - we
are starting to getting pretty complex here! Or am I doing something wrong?

Best wishes,

Mark

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Hi Oscar,

Thanks for the reply. Unfortunately your example doesn't work for me. What
version of sp and lattice do you have installed?

Package: sp
Version: 1.0-14
Date: 2013-10-15

Package: lattice
Version: 0.20-15
Date: 2013/03/24

Mark


On 7 March 2014 16:25, Oscar Perpi?an <oscar.perpinan at upm.es> wrote:

Use groups instead:

spplot(meuse["elev"], groups=ifelse(meuse$dist < 0.3, 1, 2), pch=c(1, 16))

Oscar.
-----------------------------------------------------------------
Oscar Perpi??n Lamigueiro
Dpto. Ingenier?a El?ctrica (ETSIDI-UPM)
Grupo de Sistemas Fotovoltaicos (IES-UPM)
URL: http://oscarperpinan.github.io
Twitter: @oscarperpinan


2014-03-07 15:29 GMT+01:00 Mark Payne <markpayneatwork at gmail.com>:

Hi,

I have a problem where I would like to have both the colour and the

symbol

varying in an spplot plot. Unfortunately, specifying a list of pch values
doesn't seem to work. See the following example

library(sp)
data(meuse)
coordinates(meuse) <- ~x +y
#Lets plot the elevation
spplot(meuse,"elev")
#And now the distance
spplot(meuse,"dist")
#Lets plot the points close to the river with open points
spplot(meuse,"elev",
       colorkey=TRUE,
       pch=ifelse(meuse$dist<0.3,1,16))

What I'm aiming for is to have all the points close to the river open
circles (pch=1), and all the points further from the river to be closed
(pch=16). However, the pch symbols don't seem to be propigating through
into the panel function correctly. The problem seems to arise somewhere

the

Fill.call.groups() function, but I can't quite figure out where....

This type of trick is legitimate in lattice, which is where my

inspiration

came from eg:

x <- rnorm(1000)
y <- rnorm(1000)
z <- sqrt(x^2 + y^2)
xyplot(y~x,pch=ifelse(z<1,16,1),asp="iso",cex=1)

As you can see, I have managed to change the symbol according  to the
distance from the centre.

Am I asking too much of spplot to try and achieve this type of thing - we
are starting to getting pretty complex here! Or am I doing something

wrong?

Best wishes,

Mark

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        [[alternative HTML version deleted]]