How to define finite difference approximation for first order derivative

asked 2016-01-25 19:09:28 +0100

Orange
23 ●1 ●5

updated 2022-10-15 13:30:18 +0100

FrédéricC

5206 ●3 ●43 ●114

I need to define $$y1(k)=\frac{y_{k+1}-y_{k-1}}{2*h}$$

in sage so that sage can differ between symbolic $$y_{k+1}$$ and $$y_{k}$$.

Would somebody please help?

answered 2016-01-26 09:22:44 +0100

tmonteil
27413 ●31 ●204 ●517 http://wiki.sagemath.o...

The question is not clear to me, why not simply do:

sage: Y = [1,2,4,3,7,2,1]
sage: h = 0.1
sage: [(Y[k+1]-Y[k-1])/h for k in  range(1,len(Y)-1)]
[30.0000000000000,
 10.0000000000000,
 30.0000000000000,
 -10.0000000000000,
 -60.0000000000000]

edit flag offensive delete link

Comments

$y_{k+1} $ and $y_k$ needs to remain unknown till the formation of equation, so that they can act as variables in the linear system. My interest is to automate the finite difference method in sage. Should I need to define some new data structure. Thanks for responding though!!!

Orange ( 2016-01-28 13:14:29 +0100 )edit

add a comment

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

How to define finite difference approximation for first order derivative

1 Answer

Comments

Your Answer

Question Tools

Stats

Related questions

How to define finite difference approximation for first order derivative edit

1 Answer

Comments

Your Answer

Question Tools

Stats

Related questions

How to define finite difference approximation for first order derivative