On 06/01/2022 22:19, Oscar Benjamin wrote:
On Thu, 6 Jan 2022 at 21:23, David Bailey wrote:
On 06/01/2022 16:41, Oscar Benjamin wrote:
You can use replace to make arbitrary conditions on substitution.
There are different syntaxes so here's how you do it using wild
pattern-matching:
In [15]:
On Thu, 6 Jan 2022 at 21:23, David Bailey wrote:
>
> On 06/01/2022 16:41, Oscar Benjamin wrote:
> > You can use replace to make arbitrary conditions on substitution.
> > There are different syntaxes so here's how you do it using wild
> > pattern-matching:
> >
> > In [15]: expr = (a*x**14 + b*x +
On 06/01/2022 16:41, Oscar Benjamin wrote:
You can use replace to make arbitrary conditions on substitution.
There are different syntaxes so here's how you do it using wild
pattern-matching:
In [15]: expr = (a*x**14 + b*x + c)
In [16]: expr
Out[16]:
14
a⋅x + b⋅x + c
In [17]: w =
On Thu, 6 Jan 2022 at 14:41, David Bailey wrote:
>
> Dear group,
>
> A substitution like this is easy to make with SymPy:
>
> (a*x**2+b*x+c).subs(x,y)
>
> However, how can I make a conditional substitution, such as:
>
> a) One that would replace even powers of x only.
>
> b) One which would
Dear group,
A substitution like this is easy to make with SymPy:
(a*x**2+b*x+c).subs(x,y)
However, how can I make a conditional substitution, such as:
a) One that would replace even powers of x only.
b) One which would replace even powers of x by y**(n/2) resulting in
a*y**7+b*x+c? I.e. one
consider the sympy expressions -
a = a_1*e_1+...+a_n*e_n
b = b_1*e_1+...+b_n*e_n
where the a_i's and the b_i's are commutative sympy expressions and the
e_i's are non-commutative symbols and you have a dictionary
mul_dict = {e_i*e_j: f(e_i,e_j)}
if mul_dict is fully populated then
a*b =
On 04/27/2013 12:40 PM, Alan Bromborsky wrote:
consider the sympy expressions -
a = a_1*e_1+...+a_n*e_n
b = b_1*e_1+...+b_n*e_n
where the a_i's and the b_i's are commutative sympy expressions and the
e_i's are non-commutative symbols and you have a dictionary
mul_dict = {e_i*e_j: f(e_i,e_j)}
It should work with a custom dictionary. At the very least, it will
work with any iterator or (old, new) pairs.
You could also make f symbolic and unevaluated by default, then call
doit after the substitution. It won't be 100% efficient if the same f
will appear more than once, though.
Aaron
