function [ITR, ITE, TTR, TTE] = KFCV(I,O,K)

rand('state',sum(100*clock));
[N na] = size(I);
if N < na
    I = I';
    z = N;
    N = na;
    na = z;
    clear z
end

[q Q] = nc(O); % q = number of classes, Q = classes names
if q < 6
    Q(6) = -999;
    if q < 5
        Q(5) = -999;
        if q < 4
            Q(4) = -999;
            if q < 3
                Q(3) = -999;
            end
        end
    end
end

C1 = []; C2 = []; C3 = []; C4 = []; C5 = []; C6 = []; 
N(1:6) = 0;

for i = 1:q
    C = I(find(O==Q(i)),:);
    class{i} = C;
    N(i) = size(C,1);
end

n=floor(N/K);
nn = sum(n);

for k = 1:(K-1)
    ITe = zeros(nn,na);
    TTe = zeros(nn,1);

    w = size(class{1},1);
    for i = 1:n(1)
        a = ceil(w*rand(1,1));
        ITe(i,:) = class{1}(a,:);
        class{1}(a,:) = [];
        w = w - 1;
        TTe(i,:) = Q(1);
    end

    w = size(class{2},1);
    for i = 1:n(2)
        a = ceil(w*rand(1,1));
        ITe(n(1)+i,:) = class{2}(a,:);
        class{2}(a,:) = [];
        w = w - 1;
        TTe(n(1)+i,:) = Q(2);
    end

    if q > 2
        w = size(class{3},1);
        for i = 1:n(3)
            a = ceil(w*rand(1,1));
            ITe(n(1)+n(2)+i,:) = class{3}(a,:);
            class{3}(a,:) = [];
            w = w - 1;
            TTe(n(1)+n(2)+i,:) = Q(3);
        end 
        if q > 3
            w = size(class{4},1);
            for i = 1:n(4)
                a = ceil(w*rand(1,1));
                ITe(n(1)+n(2)+n(3)+i,:) = class{4}(a,:);
                class{4}(a,:) = [];
                w = w - 1;
                TTe(n(1)+n(2)+n(3)+i,:) = Q(4);
            end 
            if q > 4
                w = size(class{5},1);
                for i = 1:n(5)
                    a = ceil(w*rand(1,1));
                    ITe(n(1)+n(2)+n(3)+n(4)+i,:) = class{5}(a,:);
                    class{5}(a,:) = [];
                    w = w - 1;
                    TTe(n(1)+n(2)+n(3)+n(4)+i,:) = Q(5);
                end 
                if q > 5
                    w = size(class{6},1);
                    for i = 1:n(6)
                        a = ceil(w*rand(1,1));
                        ITe(n(1)+n(2)+n(3)+n(4)+n(5)+i,:) = class{6}(a,:);
                        class{6}(a,:) = [];
                        w = w - 1;
                        TTe(n(1)+n(2)+n(3)+n(4)+n(5)+i,:) = Q(6);
                    end                     
                end
            end
        end
    end

    ITr = [class{1};class{2}];
    if q > 2
        ITr = [ITr;class{3}];
        if q > 3
            ITr = [ITr;class{4}];
            if q > 4
                ITr = [ITr;class{5}];
                if q > 5
                    ITr = [ITr;class{6}];
                end
            end
        end
    end
    TTr = [repmat(Q(1),size(class{1},1),1);repmat(Q(2),size(class{2},1),1)];
    if q > 2
       TTr = [TTr;repmat(Q(3),size(class{3},1),1)];
       if q > 3
           TTr = [TTr;repmat(Q(4),size(class{4},1),1)];
           if q > 4
               TTr = [TTr;repmat(Q(5),size(class{5},1),1)];
               if q > 5
                   TTr = [TTr;repmat(Q(6),size(class{6},1),1)];
               end
           end
       end
    end
    ITR{k} = ITr;
    ITE{k} = ITe;
    TTR{k} = TTr;
    TTE{k} = TTe;
end

for i = 1:q
    N(i) = size(class{i},1);
end

ITR{K} = []; TTR{K} = [];
for i = 1:K
    for j = 1:(i-1)
        ITR{i} = [ITR{i}; ITE{j}];
        TTR{i} = [TTR{i}; TTE{j}];
    end
end
    
ITE{K} = [class{1};class{2}];
if q > 2
    ITE{K} = [ITE{K}; class{3}];
    if q > 3
        ITE{K} = [ITE{K}; class{4}];
        if q > 4
            ITE{K} = [ITE{K}; class{5}];
            if q > 5
                ITE{K} = [ITE{K}; class{6}];
            end
        end
    end
end

TTE{K} = [repmat(Q(1),N(1),1); repmat(Q(2),N(2),1)];
if q > 2
    TTE{K} = [TTE{K}; repmat(Q(3),N(3),1)];
    if q > 3
        TTE{K} = [TTE{K}; repmat(Q(4),N(4),1)];
        if q > 4
            TTE{K} = [TTE{K}; repmat(Q(5),N(5),1)];
            if q > 5
                TTE{K} = [TTE{K}; repmat(Q(6),N(6),1)];
            end
        end
    end
end