Subscripted assignment dimension mismatch (size [1 x 1] ~= size [1 x :?])

Hi, I wanted to be:

arr(2,1) = arr(2,1) + abs(5.0 minus 5.1);% where I(1,a) is 5.0 and I(1,a+1)is 5.1

Why couldn't I add the below two together? I got this error message: Subscripted assignment dimension mismatch (size [1 x 1] ~= size [1 x :?]).

Function 'MATLAB Function' (#620.435.485), line 23, column 2:

"arr(count,1) = arr(count,1) + abs(I(1,a)-I(1,a+1))"

Launch diagnostic report.

'I' is declared in worskspace as:

I =[5.0000    5.1000    5.2000    5.2000
    90.0000   85.0000   80.0000   20.0000]

 integ_signal=zeros(5,4);
 a=zeros(10);
 arr=zeros(5,4);
 count=2;
a=1;

 arr(count,1) = arr(count,1) + abs(I(1,a)-I(1,a+1));

[Azzi Abdelmalek]

What is the problem? your code works

[want2know]

 Dear Sir, thanks for your reply, 
I got this error message: Subscripted assignment dimension mismatch (size [1 x 1] ~= size [1 x :?]).

Function 'MATLAB Function' (#620.435.485), line 23, column 2:

"arr(count,1) = arr(count,1) + abs(I(1,a)-I(1,a+1))" Launch diagnostic report. Do you mean there is nothing wrong to add these two? arr(count,1) = arr(count,1) + abs(I(1,a)-I(1,a+1));

[Azzi Abdelmalek]

Post the entire code

[want2know]

The complete code is here: and the system:http://imgur.com/poQw0wb

function integ_signal= fcn(I,V,count,oldval)

 integ_signal=zeros(5,1);
 a=zeros(10);
 arr=zeros(2,4);
 %b=zeros(10);
 integ_signal=oldval; 
 coder.extrinsic('load');
 load('data.mat','I');
a=1;
%b=1;
 if count==1
         integ_signal(count,1) = 10; % Initial Condition
 end

 if count>1
 %integ_signal(count,1)= integ_signal(count-1,1);
 integ_signal(count,1)=  integ_signal(count-1,1);
 arr(count,1) = integ_signal(count,1);
 arr(count,1) = arr(count,1) + abs(I(1,a)-I(1,a+1));
% test_signal=integ_signal 
 end
 a=a+1;
% b++;
end

[Azzi Abdelmalek]

We can't test your code

[want2know]

May I know what do you mean? I just don't understand why it runs perfectly if I put it in Matlab workspace, however, when it is in Matlab Function Block, i got the above error.

[Azzi Abdelmalek]

We can't test your code, because we need to load your data, and we have to do it with Simulink model