Can I use parse_expr to parse an expression such as
"a1*x1**2+a2*x1+a3+a4*x1*x2+a5*x2**2" and inject the symbols into globals
or locals namespace?
Looks like auto_symbol is not doing this. So I have to manually inject each
symbol using sympy.var() method.
exp0=parse_expr("a1*x1**2+a2*x1+a3+a4*x1*x2+a5*x2**2",transformations=(auto_number,auto_symbol))
exp0.subs(a1,10)
---------------------------------------------------------------------------NameError
Traceback (most recent call
last)<ipython-input-4-19dc46bbe490> in <module>()----> 1 exp0.subs(a1,10)
NameError: name 'a1' is not defined
But after my hack:
for each_sym in exp0.atoms(sympy.Symbol):
sympy.var(each_sym.__str__())
exp0.subs(a1,10)
2*x1 + a3 + a4*x1*x2 + a5*x2**2 + 10*x1**2
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