Re: Help with problems with symbolic package

[Markus Mützel]

Am 07. November 2020 um 17:56 Uhr schrieb dariobc@inventati.org:
> >> 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 falsa, 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!
> 
> > Please, let the list know if that works for you.
> 
> I will, but when it actually works.
> 
> Happy hacking!
> Darío

Please, keep the mailing list in CC. Other people are probably more able to 
help you.

Markus