[Math] epsilon algebra and why is it important in Numerical Analysis
numerical methods
My professor is using the following slides:
What is epsilon algebra and why is it important in Numerical Analysis?
Best Answer
This is a question you should ask your professor.
If they have not made it clear, then many students in the class are probably wondering about that.
The different epsilons represent small errors.
That "epsilon algebra" is nothing but first order approximation of errors.
All terms including products of epsilons is considered small and is thrown away.
All that is left is the main term without any epsilons and terms linear in the epsilons.
When errors are small, such calculations give a decent approximation of propagation of errors.
Errors are inevitable in numerical analysis, and it is important to understand how big an error you make in a calculation if you start with a given error.
There are a number of sources of error, so it is convenient to have several epsilons.
Not sure what level you are looking for, but you might have a look at:
Numerical Methods for Scientists and Engineers, R. W. Hamming
Analysis of Numerical Methods, Isaacson and Keller
Numerical Mathematics and Computing by E. Ward Cheney and David R. Kincaid
Numerical Analysis, Burden and Faires
Theoretical Numerical Analysis: A Functional Analysis Framework, K. Atkinson, W. Han
The first two are Dover books, so the price is great, the last two are lots of dough. I do not have the last one, but it looks worthwhile checking out. The others I refer to often.
I think you can peruse them all online.
You might also want to check these out these other MSE postings:
The following books cover all the topics that you mention rigorously. They are required reading in the field of numerical analysis and require a solid background in pure mathematics.
Higham, N. J: "Accuracy and stability of numerical algorithms", SIAM, (2002)
Golub, G. H and van Loan, C. : "Matrix computations", 4th edition. John Hopkins University Press, (2013)
Best Answer
This is a question you should ask your professor. If they have not made it clear, then many students in the class are probably wondering about that.
The different epsilons represent small errors. That "epsilon algebra" is nothing but first order approximation of errors. All terms including products of epsilons is considered small and is thrown away. All that is left is the main term without any epsilons and terms linear in the epsilons.
When errors are small, such calculations give a decent approximation of propagation of errors. Errors are inevitable in numerical analysis, and it is important to understand how big an error you make in a calculation if you start with a given error. There are a number of sources of error, so it is convenient to have several epsilons.