Error using str2sym (line 213)

Hello!

I receive an error while running the following section:

   syms V I R fR L dI Ka I w
   str2sym('V == I*(R+fR) + L*dI + Ka*I*w')

I get the error

Error using str2sym (line 213)
Unable to convert string to symbolic expression:
Error: Unexpected MATLAB expression.

After looking inside the error with dbstop if error, I found the variable 'I' is treated as special character. why so?

[madhan ravi]

Would you mind explaining why you want str2sym command when you have already defined the variables using syms command?

[Tiasa Ghosh]

I am using a MATLAB toolbox which take symbolic equations as input. I have the equations as strings in a cell array and using a loop I need to use str2sym.

[madhan ravi]

Cool good that you found an answer.:)

Answer 1

[Walter Roberson]

This is a bug involving use of the variables I or J or 'Pi' or 'PI' or 'pI'. Also, you cannot use if in an expression, and i and j will be translated into 1i .

Those are the only one-character and two-character variable names that are affected.

[Tiasa Ghosh]

Thanks! :) I will keep these in mind.