Negative distance weight function
Syntax
Z = negdist(W,P)
df = negdist('deriv')
Description
negdist is a weight function. Weight functions apply weights to an input to get weighted inputs.
negdist(W,P) takes these inputs,
and returns the S x Q matrix of negative vector distances.
negdist('deriv') returns '' because negdist does not have a derivative function.
Examples
Here we define a random weight matrix W and input vector P and calculate the corresponding weighted input Z.
W = rand(4,3);
P = rand(3,1);
Z = negdist(W,P)
Network Use
You can create a standard network that uses negdist by calling newc or newsom.
To change a network so an input weight uses negdist, set net.inputWeight{i,j}.weightFcn to 'negdist'. For a layer weight set net.inputWeight{i,j}.weightFcn to 'negdist'.
In either case, call sim to simulate the network with negdist. See newc or newsom for simulation examples.
Algorithm
negdist returns the negative Euclidean distance:
z = -sqrt(sum(w-p)^2)
See Also
sim, dotprod, dist
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