R help - Dec 2002 - Help: add arrows on a filled.contour figure

Dear All

I would like to use filled.contour to plot something with arrows on it. I did it
in this way:

filled.contour(1:nx,1:nz,u,col=gray(rev((0:20/20))))
for (j in zseq ) for (i in xseq) arrows(i, j,
i+u[i,j],j+w[i,j],length=angleng,angle=angarrow,code=2,
lwd=1,col="black")

The peoblem is that the arrows use the whole device area, including the key on
the right hand side of the filled contour. Does anyone know how to work out this
problem?

Many thanks for your kind reply.
Dr Zhiqiang Cui
School of Geography and Environmental Sciences
The University of Birmingham
Edgbaston, Birmingham
B15 2TT

You need to use the 'plot.axes' argument.  See the help page.

Try this:

filled.contour(1:nx,1:nz,u,col=gray(rev((0:20/20))), plot.axes = { for (j
in zseq ) for (i in xseq)
arrows(i,j,i+u[i,j],j+w[i,j],length=angleng,angle=angarrow,code=2,
lwd=1,col="black") })


-roger
_______________________________
UCLA Department of Statistics
rpeng at stat.ucla.edu
http://www.stat.ucla.edu/~rpeng

On Wed, 4 Dec 2002, Z Cui wrote:
> Dear All
> 
> I would like to use filled.contour to plot something with arrows on it. I
did it in this way:
> 
> filled.contour(1:nx,1:nz,u,col=gray(rev((0:20/20))))
> for (j in zseq ) for (i in xseq) arrows(i, j,
i+u[i,j],j+w[i,j],length=angleng,angle=angarrow,code=2,
lwd=1,col="black")
> 
> The peoblem is that the arrows use the whole device area, including the key
on the right hand side of the filled contour. Does anyone know how to work out
this problem?
> 
> Many thanks for your kind reply.
> Dr Zhiqiang Cui
> School of Geography and Environmental Sciences
> The University of Birmingham
> Edgbaston, Birmingham
> B15 2TT
> 
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> R-help at stat.math.ethz.ch mailing list
> http://www.stat.math.ethz.ch/mailman/listinfo/r-help
>