How to use 'Switch case' with Matlab Function Block in Simulink?

I'm able to run the following code in MATLAB:

n = input('n: ');
x = 3;
y = 2;
switch n
    case 1
        z = (x-y)/2
    case 2
        z = (x+y)/2
end

I want the 'n' value to come from a constant (or any other input block), which goes to MATLAB Function Block, and display the output when I simulate the Simulink model. Something like this:

I edited the Function Block's code as follows:

function result = fcn(n)
%#codegen
x = 3;
y = 2;
switch n
    case 1
        z = (x-y)/2
    case 2
        z = (x+y)/2
end

Its giving me several errors:

Can someone tell me what is wrong with my code or any other fixes to make this thing work?

Thanking You, Harshil

Answer 1

[Azzi Abdelmalek]

What if n is different from 1 and 2? Try this

function result = fcn(n)
%#codegen
x = 3;
y = 2;
z=0;
switch n
  case 1
      z = (x-y)/2
  case 2
      z = (x+y)/2
end

[Harshil Patel]

I'm sorry! It still gives the same errors. 'n' can be anything actually. I have simplified a complex program so that I can explain the problem better.

[Azzi Abdelmalek]

I tested this code, it works fine. Post your real code, we can't find the problem with another code.

[Harshil Patel]

Mr. Azzi, The real code just has more variables and multiple outputs within the 'cases'. So I simplified the problem for myself to see if it works or not. Still no improvement. I tried the exact code which you posted but Simulink did not give me an output, just errors. Do I need any additional compiler? (I already have the SDK, which lets me use and simulate Matlab function blocks for general purposes). I just want the function block to take the value 1 or 2 from a 'constant' block, and display the output '0.5' or '2.5' (depending on the case) in a 'display' block, when I simulate the model in Simulink.

Thanking you, Harshil

Answer 2

[Anjum Tamboli]

</matlabcentral/answers/uploaded_files/96734/Screenshot%20(29).png>This code does not work. for first range of values output should be only at y and for second range ouput should be at y1. please suggest me the modifications to run the program successfully. Thanks and Regards Anjum

Answer 3

[cqut]

you missed otherwise + statement,you can try this:

function result = fcn(n)
%#codegen
x = 3;
y = 2;

switch n
  case 1
      z = (x-y)/2
  case 2
      z = (x+y)/2
otherwise
     z =  ??
end