[R] Plotting problems directional or rose plots

[alanm (Alan Mitchell)]

I ran the code I sent earlier and there were a few bugs.  That's what I
get for using my phone to write code.  

This works a little better.  


#direction
angle<-seq(0,350,10)

#distance factor extends to
dist = sample.int(9000,size=length(angle))

#list of colors, order corrisponds to associated angle/direction
#color.list<-c('red','blue','green','yellow','pink','black')

color.list=cm.colors(9000)[dist]

# Plot Code

dist = dist/9000

t = seq(0,360,length.out=1000)*pi/180  #want radians not degrees

circle = data.frame(x=cos(t),y=sin(t))
par(mar=c(0,0,0,0))
plot(circle$x,circle$y,type='l')

for(idx in 1:length(dist)){

t0 = seq(angle[idx],angle[idx]+10,length.out=50)*pi/180

petal0 = data.frame(x = dist[idx]*cos(t0),y = dist[idx]*sin(t0))

polygon( x=c(0,petal0$x,0),y=c(0,petal0$y,0),col=color.list[idx])
}


Alan Mitchell
alanm at crab.org



-----Original Message-----
From: alanm (Alan Mitchell) 
Sent: Wednesday, July 27, 2011 7:04 AM
To: kitty; r-help at r-project.org
Subject: RE: [R] Plotting problems directional or rose plots


I'm not sure if there are any packages that do this, but I've created
similar plots in R.  The easiest way I've found is to think in terms of
a unit circle in polar coordinates for drawing the plot.  
I haven't tested the code below, but it will give you the idea.


dist=dist/9000

t = seq(0,360,length.out=1000)*pi/180  #want radians not degrees

angle=angle*pi/180

circle$x=cos(t)
circle$y=sin(t)

plot(circle$x,circle$y,type='l')

You can use the polygon function to draw the 'petals'.

# for 0-10

t0 = seq(0,10,length.out=50)*pi/180

petal0$x = dist[1]*cos(t0)
petal0$y = dist[1]*sin(t0)

polygon( x=c(0,petal0$x,0),y=c(0,petal0$y,0),col=color.list[1])


I hope this helps.  

Alan Mitchell





-----Original Message-----
From: kitty [mailto:kitty.a1000 at gmail.com]
Sent: Tue 7/26/2011 2:20 PM
To: r-help at r-project.org
Subject: [R] Plotting problems directional or rose plots
 
Hi,

I'm trying to get a plot that looks somewhat like the attached image
(sketched in word).
I think I need somthing called a rose diagram? but I can't get it to do
what I want. I'm happy to use any library.

Essentially, I want a circle with degree slices every 10 degrees with 0
at the top representing north, and 'tick marks' around the outside in 10
degree increments to match the slices (so the slices need to be ofset by
5 degrees so the 0 degree slice actually faces north) I then want to be
able to colour in the slices depending on the distance that the factor
extends to; so for example the 9000 dist is the largest in the example
so should fill the slice, a distance in this plot of 4500 would fill
halfway up the slice.
I also want to be able to specify the colour of each slice so that I can
relate it back to the spatial correlograms I have.

I have added some sample data below.

Thank you for reading my post,
All help is greatly appreciated,
K

sample data:

#distance factor extends to
dist<-c(5000,7000,9000,4500,6000,500)

#direction
angle<-c(0,10,20,30,40,50)

#list of desired colour example, order corrisponds to associated
angle/direction
color.list<-c('red','blue','green','yellow','pink','black')

(my real data is from 0 to 350 degrees, and so I have corresponding
distance and colour data for each 10 degree increment).