Hello,
I would like to find
c2
as
0.66 + 0.34 * (1 + 1.0 / c2) - 1.0 / ln(1 + c2) - 0.7 == 0
Thus I used the function
solve
like so:
c2 = Symbol('c2')
solve(0.66 + 0.34 * (1 + 1.0 / c2) - 1.0 / ln(1 + c2) - 0.7, c2)
But I got the following error:
NotImplementedError Traceback (most recent call last)
> <ipython-input-86-f1264f7163f3> in <module>()
> ----> 1 solve(0.66 + 0.34 * (1 + 1.0 / c2) - 1.0 / ln(1 + c2) - 0.7, c2)
>
> /usr/lib/python2.7/site-packages/sympy/solvers/solvers.pyc in solve(f,
> *symbols, **flags)
> 883
> ###########################################################################
> 884 if bare_f:
> --> 885 solution = _solve(f[0], *symbols, **flags)
> 886 else:
> 887 solution = _solve_system(f, symbols, **flags)
>
> /usr/lib/python2.7/site-packages/sympy/solvers/solvers.pyc in _solve(f,
> *symbols, **flags)
> 1382 if result is False:
> 1383 raise NotImplementedError(msg +
> -> 1384 "\nNo algorithms are implemented to solve equation %s" % f)
> 1385
> 1386 if flags.get('simplify', True):
>
> NotImplementedError: multiple generators [c2, log(c2 + 1)]
> No algorithms are implemented to solve equation 3/10 - 1/log(c2 + 1) +
> 17/(50*c2)
>
I read at
http://docs.sympy.org/dev/tutorial/solvers.html#solving-equations-algebraically
</> that this error often means that the solution cannot be represented
symbolically. Is it the case of my equation?
If I can't use solve to find
c2
, then what can I use?
I already tried to use the function
roots
like so:
c2 = Symbol('c2')
roots(0.66 + 0.34 * (1 + 1.0 / c2) - 1.0 / ln(1 + c2) - 0.7, c2)
Then I got this error:
> PolynomialError Traceback (most recent call last)
> <ipython-input-94-fe98ccb57669> in <module>()
> ----> 1 roots(0.66 + 0.34 * (1 + 1.0 / c2) - 1.0 / ln(1 + c2) - 0.7, c2)
>
> /usr/lib/python2.7/site-packages/sympy/polys/polyroots.pyc in roots(f,
> *gens, **flags)
> 759 else:
> 760 try:
> --> 761 f = Poly(f, *gens, **flags)
> 762 except GeneratorsNeeded:
> 763 if multiple:
>
> /usr/lib/python2.7/site-packages/sympy/polys/polytools.pyc in __new__(cls,
> rep, *gens, **args)
> 93 return cls._from_poly(rep, opt)
> 94 else:
> ---> 95 return cls._from_expr(rep, opt)
> 96
> 97 @classmethod
>
> /usr/lib/python2.7/site-packages/sympy/polys/polytools.pyc in
> _from_expr(cls, rep, opt)
> 203 def _from_expr(cls, rep, opt):
> 204 """Construct a polynomial from an expression. """
> --> 205 rep, opt = _dict_from_expr(rep, opt)
> 206 return cls._from_dict(rep, opt)
> 207
>
> /usr/lib/python2.7/site-packages/sympy/polys/polyutils.pyc in
> _dict_from_expr(expr, opt)
> 325
> 326 if opt.gens:
> --> 327 rep, gens = _dict_from_expr_if_gens(expr, opt)
> 328 else:
> 329 rep, gens = _dict_from_expr_no_gens(expr, opt)
>
> /usr/lib/python2.7/site-packages/sympy/polys/polyutils.pyc in
> _dict_from_expr_if_gens(expr, opt)
> 266 def _dict_from_expr_if_gens(expr, opt):
> 267 """Transform an expression into a multinomial form given
> generators. """
> --> 268 (poly,), gens = _parallel_dict_from_expr_if_gens((expr,), opt)
> 269 return poly, gens
> 270
>
> /usr/lib/python2.7/site-packages/sympy/polys/polyutils.pyc in
> _parallel_dict_from_expr_if_gens(exprs, opt)
> 171 coeff.append(factor)
> 172 else:
> --> 173 raise PolynomialError("%s contains an
> element of the generators set" % factor)
> 174
> 175 monom = tuple(monom)
>
> PolynomialError: 1/log(c2 + 1) contains an element of the generators set
>
What does that mean ?
Thank you in advance for your help.
Cheers,
Camille
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sympy+unsubscr...@googlegroups.com.
To post to this group, send email to sympy@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy.
To view this discussion on the web visit
https://groups.google.com/d/msgid/sympy/8abfc70b-7c43-43e6-811d-4b8cc5372d60%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
