I wonder if any of you MATLAB whizzes out there can help me with this...
I have two 2-D matrices of the same size. They show distribution of
radiation in a target. The distributions are pretty much smooth, and mostly
hill-like, i.e. maximum is near the centre. Values range from 0 to 150
The two matrices look very similar, but are generated from a simulation with
slightly different inputs. One way to compare the distributions is by
absolute or relative difference - that's easy. Another way is
DTA works like this: For each position in matrix 1, we want the distance
from the corresponding position in matrix 2 to the nearest position in
matrix 2 with the same value as the posiiton in matrix 1. Basically, we
have to plot contours of the distributions, and the contours have to match
within a certain distance tolerance, and I'm looking at how to calculate
The only way I've yet to come up with is to calculate the distance to every
position, and it's value, then take the nearest one of the same value (or
within a 0.1 value threshold). However, this is order n-squared cacluation
time, and the matrices can get quite large (400x400 or so).
Any quicker ways of doing it?
Ian Cowley (Not Reverend) - Perfecting pedantry through practice
Check www.iancowley.co.uk for contact details!
"Some people don't understand statistics" - Ciaran Byrne