Correlation of Spatial Data

Hi, I have 2 data sets X1 and X2. Both data sets contain various entries of geo spatial data (latitude and longitude).

X1=[lat1,lon1; lat2,lon2; lat3,lon3; ....] X2 is just like X1 but different values.

X1 and X2 are different in length and I am not looking for something like row by row matching as the data is independent of the row number and only dependent on its location (latitude and longitude).

Now I need to find the spatial correlation between these data sets to show that presence of entries of data set X1 means that entries of X2 will also be in nearby location. Can some one suggest any matlab function which can help me with doing correlation of spatial data. Also if someone here has good knowledge in Statistics that can he also tell me, what sort of models and algorithms are used for such analysis.

Thanks.

[Image Analyst]

Do X1 and X2 have the same number of rows? Are they expected to match up, like the n'th row of X1 is roughly the same location as the n'th row of X2? If so, maybe just use the RMS difference to get the "average" distance X2 is away from X1???

[Shahid]

X1 and X2 are of different length. And the data is independent of the "index of row". i.e the entries are in random order.