1,587 questions
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Why doesn't Symbolics.expand work in matrices?
I'm working with Julia's Symbolics.jl and I'm trying to compare two symbolic matrices.
However, since Symbolics.isequal function checks for structural- instead of mathematical-equivalence it is ...
- 293
1
vote
2
answers
65
views
Symbolic Summation of Terms with Varying Subscripts using MATLAB
I'd like to change the subscripts of xi and eta, but none of the other posts I've found have helped. Eventually, I need to multiply the entire summation with every element in a matrix dependent on ...
- 13
1
vote
1
answer
82
views
sympy mod on formulas with custom functions
I would like to define custom sympy functions which cannot be directly evaluated, but which I do want to be able to compute some things about. For example, modular remainders. Here's my code attempt:
...
- 6,417
4
votes
2
answers
89
views
How to reduce multivariate boolean expressions
I need to model a system of several boolean expressions in 512 variables. Due to the number of variables, I found the expressions are way too large to handle normally, which is why I need a way to ...
- 41
0
votes
1
answer
48
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Solving symbolic sum with symbolic bounds and variables
Given the following sample, I'd expect sympy to find that Sum_x = 30, but for some reason this symbol is not expanded at all in the solution
from sympy import *
from sympy.abc import i
# Symbols
x = ...
2
votes
0
answers
91
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Find necessary operators for symbolic regression
I wrote a symbolic regression tool in Python. It is possible to give unary and binary operators. If nothing is specified, I want to determine potential operators. So, I want to know if there is an ...
- 143
0
votes
2
answers
88
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How to get formula of matrix product from formulas of matrices?
I have formulas defining matrices.
The result I want is the formula defining their matrix product.
At no point do I want actual matrices. Those shown below are just for illustration.
The examples I ...
- 1,185
4
votes
0
answers
122
views
Symbolic regression with integer parameters
I have a project of a symbolic regression (here on GitHub).
I use first curve_fit of scipy to find parameters with linear expressions (see fit function line 85 of file sr.py) but for non linear ...
- 143
3
votes
2
answers
103
views
Compare SymPy expressions modulo variable remapping
I want to compare two Sympy expressions and know if they are equivalent with some symbolic parameters. A first approah is to use a polynom that works well but it fails with complex expressions.
Here ...
- 143
0
votes
0
answers
13
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How can I substitude a subexpression in a equation with a variable in SageMath, when the subexpression doesn't appear in its original form?
I'm trying to use SageMath to substitute a subexpression in a formula with a variable. However, the subexpression doesn't appear in the formula in its original form and requires algebraic manipulation....
- 3,717
1
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1
answer
72
views
How to solve an equation with symbolic variable?
I have the following simple script in Octave :
pkg load symbolic
syms a
P=[[a 2 -1];[2 sym('-3/2') sym('1/2')];[-2 0 sym('1/2')]]
M=[3 4 2;8 10 6;12 16 10]
P*M
Resulting in:
[3*a + 4 4*a + 4 2*...
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0
answers
65
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Associated Legendre functions of the second kind using sympy
I am working on a project and there are some complex functions that contains the derivative of the associated Legendre functions of first and second kind, of degree one and half integer order. So I ...
user29990275
1
vote
1
answer
51
views
TypeError: cannot determine truth value of Relational when entering symbolic values
I heard the issue comes when trying to compare symbolic values, for example if i enter e^(8*x) as the initial function in the code, so I've tried evalf() with the values to turn them into numeric, but ...
- 13
-2
votes
1
answer
88
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How to use symbolic algebra in programming? [closed]
Dear Developers all around the world, I'm trying to write a program that can perform some calculations. This is going to be a part of an in house ERP.
I have one number (Total Invoice Amount) , I need ...
- 199
0
votes
1
answer
48
views
Symbolic derivative with sympy of a symbolic function
If I define a variable e.g. $ V = f(r) * x^2 $ and I choose $f(r)$ as a symbolic function with $ r = \sqrt(x^2+y^2+z^2) $. Now I take the derivative of V with respect to x and want to get the solution ...
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