Finite difference method; finding the 'Stencil'

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The discussion focuses on understanding the Finite Difference Method (FDM) stencil for approximating the second derivative at discrete nodes. Participants express confusion about the terminology, particularly what constitutes a stencil and the meaning of "maximum accuracy." One user suggests that the stencil consists of five points centered around a specific node, while others emphasize the need for a clearer understanding of the concepts before attempting a solution. The conversation highlights the importance of consulting different resources for better comprehension of FDM. Overall, clarity in terminology is essential for successfully applying the finite difference method.
the_dane
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Homework Statement


Determine the Finite Difference Method stencil for approximating a second derivative u''(x) at a discrete set of nodes with maximum accuracy for stencil of sizes (0,4) (off-centered).

My questions:
I think I am able to answer the question I am just not sure about what is asked about. First of all, what is a FDM stencil? The way I understand it the stencils is the five points (a+h*0), (a+h*1) (a+h*2), ... and (a+h*4), where the approximation is centered around a. Am I correct?

What is ment with "maximum accuracy".

Homework Equations


The standard equations for Finite difference method

The Attempt at a Solution


To be honest I have not made any attempt yet because, as mentioned above, I am not sure what I am asked about
 
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the_dane said:

Homework Statement


Determine the Finite Difference Method stencil for approximating a second derivative u''(x) at a discrete set of nodes with maximum accuracy for stencil of sizes (0,4) (off-centered).

My questions:
I think I am able to answer the question I am just not sure about what is asked about. First of all, what is a FDM stencil? The way I understand it the stencils is the five points (a+h*0), (a+h*1) (a+h*2), ... and (a+h*4), where the approximation is centered around a. Am I correct?

What is ment with "maximum accuracy".

Homework Equations


The standard equations for Finite difference method

The Attempt at a Solution


To be honest I have not made any attempt yet because, as mentioned above, I am not sure what I am asked about
You have given us nothing to work with here. It looks like you need to do some reading to understand the terminology used in the problem statement. Please do that and then make an attempt at a solution. Then we might be able to help you.
 
tnich said:
You have given us nothing to work with here. It looks like you need to do some reading to understand the terminology used in the problem statement. Please do that and then make an attempt at a solution. Then we might be able to help you.
You're right that I am not quite certain about there terminology. I am using the textbook by Levee: Finite Difference Methods for Ordinary and Partial DE.

But the terminology is not clear for me and that is Exactly what I am asking about. My answer to the question is: (a+h*0), (a+h*1), ... and (a+h*4).

Basically what I want is that someone tell me why I am right or wrong.
 
the_dane said:
You're right that I am not quite certain about there terminology. I am using the textbook by Levee: Finite Difference Methods for Ordinary and Partial DE.

But the terminology is not clear for me and that is Exactly what I am asking about. My answer to the question is: (a+h*0), (a+h*1), ... and (a+h*4).

Basically what I want is that someone tell me why I am right or wrong.
So you are giving us a guess based on almost-but-not-quite nothing. When your textbook has explained something in a way that you do not understand, it is helpful to look at other books until you find an explanation you do understand.
Are you points centered around ##a##?
 
the_dane said:
I am using the textbook by Levee: Finite Difference Methods for Ordinary and Partial DE.

I can't find that book listed anywhere. What is the author's full name?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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