hi, please i wanna convert my prog matlab to vhdl with hdlcoder, but i'm blocked and i need help.Thank you

You're problem is a MATLAB error, not VHDL. If the left is your MATLAB code, try to declare `yl` in the form `f = @(arglist)expression` (https://www.tutorialspoint.com/matlab/matlab_functions.htm)

But the Error is in the Matlab code. First write working correct Matlab code. If you did this, then you can generate VHDL. But first fix the Errors in the Matlab code. As stated in the Error message, there is no y1 defined in your code but you use it.