Calculation error?? system always gives output =[0 0 0 (value in index 3 - value in index 1) 0]

I is defined in workspace and feed to the Matlab function from a constant block in Simulink. I is timeseries object : [0 1 2 3 4; 5 6 9 11 12] oldval is the previous step of arr using memory block in Simulink. so Oldval always catches the previous value of arr.

I managed to simulate system with incorrect result.

The output arr is expected to be =[10 11 13 15 16] but I got arr=[0 0 0 5 0] I tested with various I value, and I noticed that the system always gives arr =[0 0 0 (value in index 3 - value in index 1) 0] in this example, (value in index 3 - value in index 1 = 11 minus 6 = 5)

function arr= fcn(I,count,oldval)

persistent integ_signal if isempty( integ_signal) integ_signal=zeros(1,5) end persistent a if isempty(a) a=zeros(1) end

 arr=zeros(1,5);
 ii=zeros(1,5);
 aa=zeros(2,5);
 integ_signal=oldval; 

 %coder.extrinsic('load');
 %aa=load('data.mat','I');

    if count==1
        a=1;
        ii(a)=count;
       integ_signal(1,ii(a)) = 10; % Initial Condition
    end

    if count ~= 1
        a=count;
        ii(a)=count;
       integ_signal(1,ii(a))=  integ_signal(1, ii(a)-1)+ I(2,ii(a))-I(2,ii(a)-1); 

      arr(1,ii(a)) = integ_signal(1,ii(a));
    end
    a = a + 1;

end