i need help with this message undefined function or variable matlab even the vqriqble excite

I have this code when i run the function ,I am receiving the following error message,Undefined function or variable A,how can I resolve this issue?

this is the message

Undefined function or variable 'A'.

Error in T (line 21)

df=(sum(sum(A))^-1);

function [teta]=T(X) 
global n m
p1=1;
p2=2;
t=1;
for i=2:n
    for j=2:m
        k=1;
        vect=zeros(4,1);
        for h=0:p1
            for l=0:p2
            vect(k)=X(i-h,j-l);
            k=k+1;
            end
        end
        f(t,:)= vect(2:4)
        A(t)= vect(2:4)'*vect(2:4)
        t=t+1;
    end
end
df=(sum(sum(A))^-1);
t=0;
for i=2:n
    for j=2:m
        t=t+1;
        g(t,:)=f(t,:)*X(i,j);
    end
end
teta=df*sum(g);
end

[KSSV]

It seems your n and m are not defined inside the function......

[Omer Yasin Birey]

Hi youbaa, tell us the line where you got this error please

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[KSSV]

function [teta]=T(X,n,m) 
p1=1;
p2=2;
t=1;
for i=2:n
    for j=2:m
        k=1;
        vect=zeros(4,1);
        for h=0:p1
            for l=0:p2
            vect(k)=X(i-h,j-l);
            k=k+1;
            end
        end
        f(t,:)= vect(2:4)
        A(t)= vect(2:4)'*vect(2:4)
        t=t+1;
    end
end
df=(sum(sum(A))^-1);
t=0;
for i=2:n
    for j=2:m
        t=t+1;
        g(t,:)=f(t,:)*X(i,j);
    end
end
teta=df*sum(g);
end