[GRASSLIST:10825] Re: draw gps co-ordinates with a varying circle around them

[Philipp H. Mohr]

Hello,

On Mon, 6 Mar 2006, Michael Barton wrote:

> You can also use the thematic mapper (d.vect.thematic)

> >>> I hope I explain my problem properly. I have managed, with your
> >>> help, to visualise my gps data with v.neigbors, where v.neigbors
> >>> lets me specify the size of the neigborhood diameter and then counts
> >>> how many gps points fall within each neigborhood.
> >>> What I like to do now is to visualise gps data which has long and
> >>> lat, plus a value for the size of the neigborhood around each long -
> >>> lat co-ordinate, e.g.:
> >>>
> >>> 51.298895 | 1.071705 | 0.1
> >>>
> >>> I don't want grass to count the frequency of gps co-ordinates which
> >>> fall into the neigborhood, as all of them have already been
> >>> eliminated from the data. So all I want grass to do essentially is
> >>> to visualise gps co-ordinates with varying circles around them.
> >>>
> >>> Thank you for pointing me into the right direction.
> >>>
> >>> Cheers,
> >>> Phil
> >>
> >> Give d.vect.thematic a try.
> >
> > for bubble plots also try 'd.vect.chart ctype=pie' with only one data
> > column, size column.
> > or try 'v.buffer bufcol='  (sometimes buggy)


thank you for your answers. I have tried to use d.vect.thematic, but I ran
into a few problems.
I load my data in with:

	cat grass.in | v.in.ascii out=mypoints3 x=2 y=1 cat=3 columns='cat int, x double, y double'

I can draw the vector mypoints3 without any problems. But when I try to
display this vector with:

	d.vect.thematic map=mypoints3 type=point column=cat themetype=graduated_colors themecalc=interval layer=1 icon=basic/circle
	size=5 maxsize=20 nint=4 colorscheme=blue-red pointcolor=255:0:0 linecolor=0:0:0 startcolor=255:0:0 endcolor=0:0:255 monitor=x0

I get the ERROR: No such column [cat].
Could some one please tell me how to read the data in so that it can be
used with  d.vect.thematic.

Thank you very much.
Regards,
Phil