Self-Organizing Maps classification

som_clas allows to perform a SOM synoptic classification

Usage

som_clas(
  x,
  xdim,
  ydim,
  iter = 2000,
  alpha = c(0.05, 0.01),
  dist.fcts = "euclidean",
  mode = "online",
  cores = 1,
  norm = T
)

x: data.frame. A data.frame with the following variables: x, y, time, value, var,units. See tidy_nc.
xdim: Integer. X dimension of the grid. See somgrid from kohonen package.
ydim: Integer. Y dimension of the grid. See somgrid from kohonen package.
iter: integer. Number of iterations.
alpha: vector. learning rate. See som from kohonen package for details.
dist.fcts: character. vector of distance functions to be used for the individual data layers. See som from kohonen package for details.
mode: carachter. type of learning algorithm. Default "on-line". See kohonen package for details.
cores: Integer. Parallel processing only available for "pbatch" algorithm.
norm: logical. Default TRUE. norm = TRUE is recommended for classifying two ore more variables.

A list with:

A data.frame containing the dates and the weather types.
A data frame containing the gridded data grouped by circulation types.
An object of class kohonen with all the components returned by the function som

Wehrens, R. and BuydenL. (2007) Self- and Super-organizing Maps in R: The kohonen Package Journal of Statistical Software, 21(5), 1 - 19.

# Load data
data(z500)

# SOM classification
som_cl <- som_clas(z500, xdim = 4, ydim = 4, iter = 200)