could someone explain me the IT2FLS code?

when i run it in a .m file it is running....but when i use the same in the matlab function block in simulink,i get a lot of errors like mismatch in size, dimension etc...

    function [y,yl,yr]=IT2FLS(x,X,Y)

    % y=IT2FLS(x,X,Y)
    % Compute the output of an IT2 FLS. Dongrui Wu ([e-mail]), 3/11/2011
    %
    % x: Input to the IT2 FLS. Assume the FLS has N consequents and 1 consequent. Then, x can be a 1*N vector
    %    or M*N matrix, each row corresponding to an input vector.
    %
    % X: Matrix describing the consequents part of the rulebase. Assume the rulebase has K rules:
    %    IF x1 is X11 and x2 is X21, THEN y is y1
    %    ...
    %    IF x1 is X1K and x2 is X2K, THEN y is yK
    % where X11-X2K are IT2 FSs and y1-yK are crisp intervals. Then,
    %      X=[MF of X11, MF of X21;
    %         ...
    %         MF of X1K, MF of X2K]
    % Note that each MF is represented by 9 points.
    %
    % Y: Matrix describing the consequent part of the rulebase. For the above rulebase,
    %    Y=[y1;
    %       ...
    %       yK];
    %
    % y: Output of the IT2 FLS. It has as many rows as x, each row is the output for the corresponding row of x.
    %    y=(yl+yr)/2
    %
    % yl: Lower bounds of the intervals output by the type-reducer.
    %
    % yr: Upper bounds of the intervals output by the type-reducer.
    %
    % Dongrui Wu, GE Research ([e-mail])
    %

    if nargin<3
        display('Function IT2FLS: Must have three arguments. Abort.'); return;
    end

    if size(X,1)~=size(Y,1)
        display('Function IT2FLS: X must have the same number of rows as Y. Abort.'); return;
    end

    if size(x,2)~=size(X,2)/9
        display('Function IT2FLS: The number of columns in x must be equal to the number of IT2 FSs in each row of X. Abort'); return;
    end

    y=zeros(size(x,1),1);
    yr=y; yl=y;
    for i=1:size(x,1)
        fl=ones(1,size(X,1)); fu=fl;
        for j=1:size(X,1)
            for k=1:size(X,2)/9
                fu(j)=fu(j)*mg(x(i,k),X(j,9*(k-1)+(1:4)));
                fl(j)=fl(j)*X(j,9*k)*mg(x(i,k),X(j,9*(k-1)+(5:8)));
            end
        end
        [y(i),yl(i),yr(i)]=EIASC(Y(:,1)',Y(:,2)',fl,fu);
    end

    function [y,yl,yr,l,r]=EIASC(Xl,Xr,Wl,Wr,needSort)

    %
    % function [y,yl,yr,l,r]=EIASC(Xl,Xr,Wl,Wr,needSort)
    %
    % function to implement the EIASC algorithm in:
    %
    % D. Wu and M. Nie, "Comparison and Practical Implementation of Type-Reduction Algorithms for Type-2 
    % Fuzzy Sets and Systems," IEEE International Conference on Fuzzy Systems, Taipei, Taiwan, June 2011.
    %
    % Dongrui WU, GE Research ([e-mail]), 7/18/2010
    %
    % Xl: A row vector containing the lower bounds of x
    % Xr: A row vector containing the upper bounds of x
    % Wl: A row vector containing the lower bounds of w
    % Wr: A row vector containing the upper bounds of w
    % needSort: 1 if at least one of Xl and Xr is not in ascending order. 
    %           0 if both Xl and Xr are in ascending order. Default 1.
    %y: (yl+yr)/2
    %yl: lower bound of the type-reduced output
    %yr: upper bound of the type-reduced output
    %l: switch point for yl
    %r: switch point for yr

    ly=length(Xl); XrEmpty=isempty(Xr);
    if XrEmpty;  Xr=Xl; end
    if max(Wl)==0
        yl=min(Xl); yr=max(Xr);
        y=(yl+yr)/2;  l=1; r=ly-1; return;
    end
    index=find(Wr<10^(-10));
    if length(index)==ly
        yl=min(Xl); yr=max(Xr);
        y=(yl+yr)/2; l=1; r=ly-1; return;
    end
    Xl(index)=[]; Xr(index)=[];
    Wl(index)=[]; Wr(index)=[];
    if nargin==4;  needSort=1; end

    % Compute yl
    if  needSort
        [Xl,index]=sort(Xl); Xr=Xr(index);
        Wl=Wl(index); Wr=Wr(index);
    end
    Wl2=Wl; Wr2=Wr;
    for i=length(Xl):-1:2 % Make Xl unique
        if Xl(i)==Xl(i-1)
            Wl(i)=Wl(i)+Wl(i-1);
            Wr(i)=Wr(i)+Wr(i-1); Xl(i)=[];
            Wl(i-1)=[]; Wr(i-1)=[];
        end
    end
    ly=length(Xl);
    if ly==1
        yl=Xl;  l=1;
    else
        yl=Xl(end); l=1;
        a=Xl*Wl'; b=sum(Wl); 
        while l < ly && yl > Xl(l)
            a=a+Xl(l)*(Wr(l)-Wl(l));
            b=b+Wr(l)-Wl(l); 
            yl=a/b;   l=l+1;
        end
    end

    % Compute yr
    if ~XrEmpty && needSort==1
        [Xr,index]=sort(Xr);
        Wl=Wl2(index); Wr=Wr2(index);
    end
    if ~XrEmpty
        for i=length(Xr):-1:2 % Make Xr unique
            if Xr(i)==Xr(i-1)
                Wl(i)=Wl(i)+Wl(i-1);
                Wr(i)=Wr(i)+Wr(i-1); Xr(i)=[];
                Wl(i-1)=[]; Wr(i-1)=[];
            end
        end
    end
    ly=length(Xr);
    if ly==1
        yr=Xr; r=1;
    else
        r=ly; yr=Xr(1); 
        a=Xr*Wl'; b=sum(Wl);
        while r>0 && yr < Xr(r)
            a=a+Xr(r)*(Wr(r)-Wl(r));
            b=b+Wr(r)-Wl(r); 
            yr=a/b;  r=r-1;
        end
    end
    y=(yl+yr)/2;

    function u=mg(x,xMF,uMF)

    % u=mg(x,xMF,uMF)
    % function to compute the membership grades of x on a T1 FS
    % Dongrui WU, GE Research ([e-mail]), 7/18/2010
    %
    % xMF: x-coordinates of the T1 FS
    % uMF: u-coordinates of the T1 FS; default to be [0 1 1 0]
    % u: membership of x on the T1 FS

    if nargin==2
        uMF=[0 1 1 0];
    elseif length(xMF)~=length(uMF)
        display('Function mg: xMF and uMF must have the same length. Abort.'); return;
    end

    [xMF,index]=sort(xMF); uMF=uMF(index);

    u=zeros(size(x));
    for i=1:length(x)
        if x(i)<=xMF(1)
            if xMF(1)==xMF(2)
                u(i)=1;
            end
        elseif x(i)>=xMF(end)
            if xMF(end-1)==xMF(end)
                u(i)=1;
            end
        else
            left=find(xMF<x(i),1,'last');     right=left+1;
            u(i)=uMF(left)+(uMF(right)-uMF(left))*(x(i)-xMF(left))/(xMF(right)-xMF(left));
        end
    end

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup