Re: ODE to difference equation and solution



On Thu, 18 Jan 2007 23:05:44 GMT, "Calvin Guan"
<hguan@xxxxxxxxxxxxxxxxxxx> wrote:

Hello,

I'm trying to convert an 2nd order ODE to difference equation and solve it
numerically. Here is an example.

y''=sin(x), given the IC y(0)=0 and BC y(3.14)=0. This can be solved
analytically if y'(0) is known.

I convert the ODE to DE like:

y(n+1)-2y(n)+y(n-1)=h*h*sin(n*h)

given initial value y(0)=0
and final y(m+1)=0 where h=3.14/(m+1)

This can be solved by constructing a m*m matrix. but it became very resource
demanding if m is big. I try to solve it by z-transform but I don't have the
value for y(1).

How this can be solved efficiently?


By solving numerically equation for y'(0).

See the book: "Quasilinearization and nonlinear boundary-value
problems" (Modern analytic and computational methods in science and
mathematics) by Richard Ernest Bellman

A.L.

.



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