Neural Network Toolbox

boxdist

Box distance function

Syntax

d = boxdist(pos);

Description

boxdist is a layer distance function that is used to find the distances between the layer's neurons, given their positions.

boxdist(pos) takes one argument,

• pos -- N x S matrix of neuron positions

and returns the S x S matrix of distances

boxdist is most commonly used in conjunction with layers whose topology function is gridtop.

Examples

Here we define a random matrix of positions for 10 neurons arranged in three-dimensional space and then find their distances.

• pos = rand(3,10);
  d = boxdist(pos)
  

Network Use

You can create a standard network that uses boxdist as a distance function by calling newsom.

To change a network so that a layer's topology uses boxdist, set net.layers{i}.distanceFcn to 'boxdist'.

In either case, call sim to simulate the network with boxdist. See newsom for training and adaption examples.

Algorithm

The box distance D between two position vectors Pi and Pj from a set of S vectors is:

• Dij = max(abs(Pi-Pj))
  

See Also

sim, dist, mandist, linkdist

adapt

calca

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