Find a new point x in the direction p from a point xold at which the
value of the function has decreased sufficiently, the positive
definiteness of B matrix (approximation of the inverse of the Hessian) is
preserved and no bound constraints are violated.
Returns the value, x, for which the area under the
Normal (Gaussian) probability density function (integrated from
minus infinity to x) is equal to the argument y
(assumes mean is zero, variance is one).
An implementation of the Self Organizing Maps algorithm as proposed by
Constructor for class net.sf.javaml.clustering.SOM
Create a 2 by 2 Self-organizing map, using a hexagonal grid, 1000
iteration, 0.1 learning rate, 8 initial radius, linear learning, a
step-wise neighborhood function and the Euclidean distance as distance