Dear List,
i am writing since i would like to define the output of the derivative of a
function, and i don't have a clue of how to achieve it
to explain what i wish to do, let's consider the following script
from sympy import *
u = symbols('u')
der = symbols('der')
e = symbols('e',
If you want to define advanced things you need to subclass from
Function rather than using symbols(cls=Function). For derivatives, you
should define fdiff, which should return the derivative of the
function without consideration of the chain rule. For example, search
for "fdiff" in this file to
To achieve this with lambdify you should call cse() first, then
lambdify each expression separately. We ought to build a wrapper to
make this easier (or a cse=True flag to lambdify).
Aaron Meurer
On Fri, Oct 14, 2016 at 11:06 AM, Björn Dahlgren wrote:
>
>
> On Friday, 14
On Friday, 14 October 2016 15:09:46 UTC+2, Albert Pető wrote:
>
> Hi, I plan to heavily use a function generated with lambdify from a sympy
> expression which has repeated occurences of some subexpressions.
>
This functionality is available in symengine:
Hi,
I would like to evaluate certain functions created with lambdify. Those
functions would come from rotations and would have a lot of trigonometric
function invocations in them with the same parameters. For example, lets
suppose that it would contain cos(a) many times. I plan to heavily use
Hi, I plan to heavily use a function generated with lambdify from a sympy
expression which has repeated occurences of some subexpressions.
Specifically it will have a lot of cosine and sine expressions with the
same arguments. I don't know if lambdify can notice this pattern and
evaluate that
What I am using right now dear Riccardo is the following:
Suppose that my variable sigma(define as a symbol) depends of u, but at the
same time this u is vectorial variable, which means for example in 3D the
variable will be : u = [u_0, u_1, u_2], all the components of u are defined
as