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Questions - ode

Explicit (Forward) and Implicit (Backward) Euler Methods in Python

I am trying to implement both the explicit and implicit Euler methods to approximate a solution for the following ODE: dx/dt = -kx, where k = cos(2 pi t), and x(0) = 1 Euler's methods use finite diffe...
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Savannah

python

jupyter

ode

Votes: 0

Answers: 2

Latest Answer

Usually, for Backward Euler and Trapezoidal Rule, you write the expression as a equation (or a system of equations), then solve it (i.e. find its zeros). The zeros represent the value of x[i+1]. For e...
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Aziz

Different output for equivalent code between Matlab and Julia

I have a working Matlab algorithm for the evolution of a pulse via solving the 1D wave equation. I know the code works and I can see the pulse traveling to the sides and bouncing off the walls, when p...
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Alej

matlab

julia

output

ode

Votes: 0

Answers: 1

Latest Answer

Julia arrays are designed to be fast. So, when an array is assigned to another array, the default behaviour is make the two arrays the same - same variable address, occupying the same area of memory. ...
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Francis King

Minimising root function through scipy.optimize

I have code which estimates a parameter beta in an ODE system, given that all parameters are known other than beta and the peak of the 'epidemic' simulation, is 10% of the starting population. However...
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Landon

python

function

scipy

ode

Votes: 0

Answers: 1

Latest Answer

Yes, you can do this using scipy.optimize.minimize. One approach would be as follows: from scipy.optimize import minimize def residual(x): return (peak_infections(x) - 0.1) ** 2 x0 = 0.5 res = m...
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Muhammad Mohsin Khan

Why do i receive an 'x' undefined error with ode23s but not with ode23 or ode15s in OCTAVE?

I'm trying to solve some ODEs in OCTAVE with solver ode23s (the exact same algorithm is running perfectly in Matlab) but i'm receiving an 'x' undefined error, while that doesn't happen when i'm using ...
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Alex Chatzistavris

matlab

undefined

octave

ode

Votes: 0

Answers: 1

Latest Answer

According to octave's documentation, the syntax is [T, Y] = ode23s (FUN, TRANGE, INIT, ODE_OPT) You are passing an extra model parameter which is not part of the function's signature. Also the odesys...
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Tasos Papastylianou

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