issues with syms function

Whenever I use the syms (symbolic function) code I keep getting errors, even on simple codes that I am sure they are correct.

For example this simple code

syms a [1 4]
a

The output

Error in syms (line 227)

defined = sym(zeros(1, length(args)));

Error in quiz (line 1)

syms a [1 4]

[Ameer Hamza]

What is the complete error message? Can you show the output of

which sym -all

[Reem Alblooshi]

The output I've shown above is the whole error message

This is the output to which sym -all

Applications/MATLAB_R2020a.app/toolbox/symbolic/symbolic/@sym/sym.m % sym constructor

[Walter Roberson]

There would have been more to the error message, such as an error that args was not defined, or that sym was being called as a function by is a script, or something.

[Reem Alblooshi]

[Ameer Hamza]

Have you tried changing the file sym.m installed by MATLAB? To check, run the following in the command window

edit sym.m

it will open a file. See if the first line of the file is

classdef sym < handle

[Reem Alblooshi]

yes it seems that I do have a file named sym.m, but classdef sym < handle is not the first line on the file, it doesnt even exist in the file.

[GAGANDEEP KAUR]

I also have some problem with using syms a b c d e , my program keeps on running and when I am pausing it, it is opening sym.m file.

Although first line of the file is

classdef sym< handle

If anyone can help?

[Walter Roberson]

restoredefaultpath
rehash toolboxcache
syms x

and see if that works.

I suspect you have a third-party function that is interfering with operation the Mathworks sym.m

[GAGANDEEP KAUR]

I have tried as you adviced but still it is keep on running. If possible may you please have a look at attcahed files

Answer 1

[Ameer Hamza]

Most likely scenario is that you somehow overwrote the sym.m file. The only way to fix it is to delete the current installation and reinstall MATLAB.

[Reem Alblooshi]

yes I did that and the programs is working now, thank you for your assistance.

[Ameer Hamza]

I am glad to be of help!

Answer 2

[madhan ravi]

You have a custom file named sym.m , remove it from the path or rename it.

[Reem Alblooshi]

I tried deleting the file but I keep getting this messsage

Warning: File 'sym.m' not found.

> In quiz (line 2)

although the file does exist.