The problem of self-organizing maps (SOM) in MATLAB

Question

I have a text file containing data. My text file is:

young, myopic, no, reduced, no
young, myopic, no, normal, soft
young, myopic, yes, reduced, no
young, myopic, yes, normal, hard
young, hyperopia, no, reduced, no
young, hyperopia, no, normal, soft
young, hyperopia, yes, reduced, no
young, hyperopia, yes, normal, hard

I read a way to download a text file

%young=1
%myopic=2
%no=3 etc.

load iris.txt
net = newsom(1,[1 5]);
[net,tr] = train(net,1);
plotsomplanes(net);

Error code:

??? Undefined function or plane planes method for input arguments enter network.

Answer 1

Given the text file you are showing, the LOAD function will not work. You must use TEXTSCAN to parse a text file. Then I use GRP2IDX to convert the nominal data into numeric attributes (it will assign 1,2,3, .. for each attribute value). In this case, the data becomes:

>> data =
     1     1     1     1     1
     1     1     1     2     2
     1     1     2     1     1
     1     1     2     2     3
     1     2     1     1     1
     1     2     1     2     2
     1     2     2     1     1
     1     2     2     2     3

>> labels{:}
ans = 
    'young'
ans = 
    'myopic'
    'hyperopia'
ans = 
    'no'
    'yes'
ans = 
    'reduced'
    'normal'
ans = 
    'no'
    'soft'
    'hard'

, , , ( ), - ...

%# read text file
fid = fopen('iris.txt');
D = textscan(fid, '%s %s %s %s %s', 'Delimiter',',');
fclose(fid);

%# convert nominal to numeric
%#data = cell2mat( cellfun(@grp2idx, D, 'UniformOutput',false) );
data = zeros(numel(D{1}),numel(D));
labels = cell(size(D));
for i=1:numel(D)
    [data(:,i) labels{i}] = grp2idx(D{i});
end

%# build SOM
net = newsom(data', [4 4]);
[net,tr] = train(net, data');
figure, plotsomhits(net, data')
figure, plotsomplanes(net)