[R-sig-Geo] [R-sig-GEO] data set manipulation, averaging

[karl.sommer at dpi.vic.gov.au]

Hello list

I am stuck with a problem regarding the manipulation of two data sets.

The first data set contains electromagnetic induction (EMI) readings of a
field obtained with a high sampling density,14965 records in a field 1000
by 500 m. Each reading is geo-referenced.
The second set contains soil related information (texture) taken from soil
pits of the same field at a density of 75 x 75 m resulting in 111 readings.
The position of each pit is geo-referenced as well.

I would like to calculate an average of the EMI readings in the vicinity of
the soil pits, say within a radius of 2 - 5 metres and relate this average
to the soil texture data obtained from the pits.

Averaging would also reduce the size of the EMI data set which at the
moment is too big for ordinary kriging in GSTAT.

Can this be done with a few lines of code?

Regards

_________________________________
Karl J Sommer,
Department of Primary Industries,
Catchment & Agriculture Services,
PO Box 905
Mildura, VIC, Australia 3502

Tel: +61 (0)3 5051 4390
Fax +61 (0)3 5051 4534

Email:     karl.sommer at dpi.vic.gov.au