how to solve this error when i use matlab function

Simulink does not have enough information to determine output sizes for this block. If you think the errors below are inaccurate, try specifying types

function y = fcn(R1,R2,w,f,l)

y = (1-(R1/R2)^w*exp(1)^(-f*l/R2));

[Walter Roberson]

The block diagram shows inputs R1, R2, w.

The function definition shows inputs R1, R2, w, f, l

[Fangjun Jiang]

f and l are likely parameters. Parameters are shown in the function input arguments.

[翰旭]

thank for your advice but i change the input ；problem also exist

[Walter Roberson]

Try

function y = fcn(R1,R2,w,f,l)
y = 0;
y = (1-(R1./R2).^w.*exp(-f.*l./R2);

[翰旭]

sorry! i try this code, but the same problem still occurs.

Answer 1

[Fangjun Jiang]

Make sure your function is correct. Manually give a numerical example value to obtain the resulting y value.

In the MATLAB Function block editor, click "Edit data" and specify the size of y, for example, 1, or [2,3] or whatever.