[SciPy-User] Scipy Odeint " can solve a Two-Point Boundary Value problem, of a nth Nonlinear Second-Order Differential Equation ? " Help!

freebluewater freebluedolphin@gmail....
Tue Apr 2 02:03:31 CDT 2013


Hello to everyone here,

I am trying to solve the next equation :
http://www.wolframalpha.com/input/?i=d%2Fdx%28du%2Fdx%29+%3D+%28-3%2F%28k1%29[x]%29*%28k4[x]-%28k2[x]%2Bk3[x]%29*u^
%281%2F3%29%29+*%28%28du%2Fdx%29^%282%2F3%29%29
which has 2 boundary conditions (u(x=0)=0, u(x=n(max) = m (constant) is
calculated) ...

Please, do someone know if it is possible to solve this nth nonlinear
second-order differential equation with odeint ? (1D problem - x(1,n) ,
u(x), arrays parameters:bk1-k4 calculated on each x gridpoint), depended by
an import data X, which is a 1D nth array (n grid points)

I cant understand how to use the boundary conditions, when I have an initial
at x=o of u, and for its derivative du/dx = u' at x=n, the last gridpoint
which change on every time step...

Moreover, the known parameters k1(x)--k4(x), how I will use them inside the
callback function which evaluates the ODEs? Do I have to use a K parameter
like that:
def my_function(u, K): ... and then ... k1 = K[0] ... etc ? this script will
be inside a time loop, so these parameters are changing on each time loop,
as the import data Array X change on each time step (new value is being
calculated on each time step)

Theoretically this equation could be solved using the Newton iteration
method, but its too complicated for my knowledge and my little experience to
do that.

Please, any help will be more than welcome!!!
Kas



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