Re: Help with problems with symbolic package

I didn't CC my answer to Markus. Here you have it now:

[I don't repeat all the first message as long as it is currently solved 
(by installing the last alpha)]

-------- Original Message --------
Date: 2020-11-07 16:56
 From: [email protected]
To: Markus Mützel <[email protected]>

>> Hello, I recently installed Octave and I need to use the symbolic
>> package.
>> I downloaded it from the sourceforge of Octave, but I've had some
>> problems
>> when I started using it. I have installed Python 3.9 and the last
>> version of
>> the sympy module.
> 
> I believe the current version of the symbolic package doesn't work
> correctly with the latest version of sympy.
> 
> The next version of Octave for Windows will ship the symbolic package
> with the necessary dependencies. You could try the release candidate
> version 6.0.92 that you can download from here:
> https://alpha.gnu.org/gnu/octave/?C=M;O=D
> 
> After installing it, just load the symbolic package with "pkg load 
> symbolic".

It worked but there are still problems with some functions:

<--beggining of code-->

>> pkg load symbolic
>> syms x real
Symbolic pkg v2.9.0: 
/usr/lib/python3.8/site-packages/mpmath/ctx_mp_python.py:892: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if other is 0:
/usr/lib/python3.8/site-packages/mpmath/ctx_mp_python.py:986: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if other is 0:
/usr/lib/python3.8/site-packages/sympy/solvers/diophantine.py:3186: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if feasible is 1:  # it's prime and k == 2
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:509: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:529: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:542: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:549: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/mpmath/ctx_mp_python.py:892: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if other is 0:
/usr/lib/python3.8/site-packages/mpmath/ctx_mp_python.py:986: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if other is 0:
/usr/lib/python3.8/site-packages/sympy/solvers/diophantine.py:3186: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if feasible is 1:  # it's prime and k == 2
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:509: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:529: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:542: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
/usr/lib/python3.8/site-packages/sympy/plotting/plot.py:549: 
SyntaxWarning: "is" with a literal. Did you mean "=="?
   if self.xscale is 'log':
Python communication link active, SymPy v1.4.
>> f(x)=x^2
f(x) = (symfun)

    2
   x

>> fplot(f)
error: isalnum: not defined for class
error: called from
     fplot at line 108 column 3
>> fplot(f(x))
error: isalnum: not defined for class
error: called from
     fplot at line 108 column 3

<--end of code-->

So, at least I can work with the real variable, but I have to plot 
functions and so... Do you know how to solve this? And, about the 
SyntaxWarning, AFAIK, in Python 'a is b' is like the identity 
comparison... I think all the lines were it showed a warning would 
return false, as long as and object just created for the comparison and 
one stored as a variable are obviously not the same. But that might be a 
Python problem. I will check on my own, but please tell me if you know 
how to make the functions like 'fplot(symfun(syms))' work.

However, thanks a million for solving my first problem!

Happy hacking!
Darío