All Questions
6 questions
0
votes
1
answer
153
views
How to use a custom OdeSolver in Scipy's solve_ivp
In Scipy's solve_ivp documentation, we see the method argument can be either a string or a user-defined ...
- 307
3
votes
2
answers
2k
views
Inaccurate results of integration using scipy solve_ivp
I am trying to use solve_ivp to solve the following 1st order ODE:
$$ \frac{d \rho}{d z} = \frac{m \theta}{(1+\theta z)} \, \rho, $$
subject to $\rho(z=0)=1$, where ...
- 33
1
vote
1
answer
121
views
Numerical integrator for $a'(t)=e^{-a(t)}f(t)$
Suppose I know a function $f(t)$ and all its derivatives in $t$ in closed form. Given $a(0)$ and some $t_0>0$, I'm looking for an explicit integrator that can estimate $a(t_0)$, where $a(\cdot)$ ...
- 1,433
0
votes
1
answer
114
views
calculating integral for an ODE system
I have an ODE system defining a mathematical model of a biological system, say
$$
\frac{da}{dt}=f_1(a,b,\ldots,z,p)\\
\frac{db}{dt}=f_2(a,b,\ldots,z,p)\\
\cdots\\
\frac{dz}{dt}=f_n(a,b,\ldots,z,p)
$$
...
- 103
-1
votes
1
answer
6k
views
Using scipy.odeint to solve coupled equations [closed]
I have a set of three coupled autonomous equations:
${y_{1}}\prime = y_{1}(\frac{\Omega_{m}}{y_{1}^3} + \frac{y_{3}^2}{6.0} + \frac{V(y_{2})}{2.H_{0}^2})$
$y_{2}\prime = y_{3}$
$y_{3}\prime = -3\frac{...
- 111
13
votes
2
answers
9k
views
Which Runge-Kutta method is more accurate: Dormand-Prince or Cash-Karp?
I simply want to know whether the Dormand-Prince Numerical Method
or the Cash-Karp Numerical Method
is more accurate.
- 233