[R-sig-Geo] plotting Football field ball pattern data

[Miguel Eduardo Gil Biraud]

Hi,

I was going to post a similar question as I am also a fresh new user of R.

In my case I have between 10 million and 20 million latitude,
longitude pairs and want to get an image in which each pixel has a
color that is a function of the amount of positions that would fall
into the spatial bin corresponding to the pixel size. I understand
that this would be akin to a 2D histogram of my data and resemble a
density plot.

The way I started doing that was importing the table with read.table()
and then converting it to a PPP object providing the adequate bounds.
The first problem I face is that when I try to put all the points into
the PPP object I get a memory failure.

To keep experimenting I lowered the number of points I import and
played around with the density function available in spatstat but
while I can see its uses when you have few points, in my case the
patters would get diluded very fast even for small values of sigma and
I am afraid it would not represent the data faithfully.

On the other hand the function quadratcount returns very fast results
for a high number of partitions in the X and Y axis and I could
certainly use the results it provides, if it wouldn't be for the fact
that when I try to plot it, I get the grid and the point count inside
each cell. Is there any way to convert the output of gridcount into a
colored plot in the same spirit of the one you get when you do a
plot(density())?

Hope it wasn't too confusing. As you can see I've tried to take a jab
at it on my own, but it is proving more complicated than I expected!
:)

Cheers,
Miguel

On Fri, Jan 30, 2009 at 06:09, srinivasa raghavan
<srinivasraghav at gmail.com> wrote:
> Hi r-sig-geo team,
>
> I am a new user of R 2.8.1 in windows 2003. I have a data set of football
> ball pattern data. The data is for multiple matches. The variables are :
>
> match: The code number of the match.
> period: First half or second half denotted by 1 or 2.
> pitchX:  The x co-ordinate of the field.
> pitchy: The y-co-ordinate of the field.
> seconds: The time point.
>
> I am interested to draw the football graph/diagram and then plot the above
> data.
>
> Can any one let me know the right functions/packages which can help me in
> this regard.
>
> thanks in advance.
>
> warm regards,
> srinivas
> statistical analyst.
>
>        [[alternative HTML version deleted]]
>
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