All Questions
Tagged with numerical-methods python
763 questions
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Why doesn’t the barycenter method detect subpixel displacements where correlation does?
I’m working with X-ray imaging data.
I have a reference image containing a structured pattern, and a sample image where this pattern is slightly distorted due to the presence of a physical sample.
My ...
- 111
3
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5
answers
233
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Why no floating point error occurs in print(0.1* 100000) vs (Decimal(0.1)*100000) due to FP representation of 0.1?
I am studying numerical analysis and I have come across this dilemma.
Running the following script,
from decimal import Decimal
a = 0.1 ;
N = 100000 ;
# product calculation
P = N*a
# Print product ...
2
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2
answers
97
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Find correct root of parametrized function given solution for one set of parameters
Let's say I have a function foo(x, a, b) and I want to find a specific one of its (potentially multiple) roots x0, i.e. a value x0 such that foo(x0, a, b) == 0. I know that for (a, b) == (0, 0) the ...
- 531
-1
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18
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PySHtools library script
I have two perfectly defined sets of SH coefficients obtained through rigorous models in two text files.
I have read that PyShtools has the necessary classes and functions to plot them in a restricted ...
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0
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53
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Phase Portrait of Coupled ODEs Not Matching Expected Graph in Python (SciPy)
I’m trying to generate a phase portrait for a system of coupled ordinary differential equations (ODEs) using Python’s scipy.integrate.solve_ivp. The system models the frequency of cooperators (x) and ...
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votes
1
answer
50
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Producing bifurcation diagram of logistic map including unstable points
I'm trying to produce a bifurcation diagram such as this one.
Typical bifurcation diagrams only include stable fixed points, which are attractive (nearby points get pulled towards the fixed point upon ...
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1
answer
62
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Difference in output of sympy.binomial vs scipy.special.comb
Why does the following code that calls comb produce the wrong output?
from scipy.special import comb
from sympy import binomial
def coup(n=100, m=10):
expectation = 0
for j in range(1, n + 1):
...
- 2,599
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45
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How to simulate in python the superconducting density of states of a BCS superconductor with YSR (yu-shiba-rusinov) with 1D chain tight binding model
I try to simulate the following problem:
Compute the density of states numerically of a BCS superconductor with magnetic impurities using the tight binding model of 1D chain with periodically border ...
0
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0
answers
80
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Minimum image convention for a MD simulation in Python
I'm trying to implement a simple molecular dynamic simulation in Python for N atoms with periodic boundary conditions using minimum image convention.
Here is my code:
import numpy as np
import ...
- 47
0
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0
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33
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Simple MD simulation for N atoms with PBC in Python
I'm trying to implement a simple molecular dynamic simulation in Python for N atoms with periodic boundary conditions while allowing coordinate wrapping to visualize the atoms interacting through
...
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1
answer
65
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Molecular dynamic simulation using velocity verlet in Python
I'm trying to implement a simple MD simulation in Python (I'm new to this),I'm using LJ potential and force equations along with Verlet method.
I posted another question about the same code yesterday ...
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1
vote
1
answer
50
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MD simulation using velocity verlet in Python
I'm trying to implement a simple MD simulation in Python (I'm new to this),I'm using LJ potential and force equations along with Verlet method:
def LJ_VF(r):
#r = distance in Å
#Returns V in (...
- 47
0
votes
1
answer
35
views
Steps approximation for time series scatter with mean changing every K number of steps using BIC
First, the synthetic data used is generated the following the way:
import sympy as sp
import numpy as np
import matplotlib.pyplot as plt
import random
import math
np.random.seed(2)
n_samples = 180
...
- 71
0
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0
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35
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Optimizing a numerical integration that involves matrices using sympy
The expression I'm integrating is
Where the latent variables are sampled from the a multivariate distribution as following:
And the random variables w_n given a latent variable is sampled from a ...
- 71
2
votes
1
answer
89
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How to solve the derivative of the expression with respect to D?
The integral is
Where the variables follow the following distribution:
Thus, the integral becomes:
Now, my code in python is to integrate the expression with \(W_{1:3}\) being \(1,2,3\) ...
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