Talk:Lagrange polynomial

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I did a complete overhaul of the page. At the moment it is quite technical, maybe someone could add a practical example. MathMartin 16:58, 25 Apr 2004 (UTC)

Good work, sorry for all the errors, they were mine... Nixdorf 18:18, 25 Apr 2004 (UTC)
No sweat, I have not found any big errors. The article was just a bit small and blurry. I hope it is better now. Is there any reason you used t instead of x as a variable ? MathMartin 22:55, 25 Apr 2004 (UTC)
Not really, use x if you prefer. I come from physics so I like to think of it as "time", but generally, perhaps x is better. Nixdorf 16:33, 26 Apr 2004 (UTC)

Some one shoud add that \ell_j can also be writen as

\ell_j=\frac{f(x)}{(x-x_j)\,f'(x_j)}

with

f(x):= \prod_{i=0}^{k} (x-x_i)

[edit] Multiplying by four

Do we really have to multiply everything by four, so that we get integers? It gave me something of a double-take. I think it would be more intuitive the other way, so it is easier to figure out what numbers came from where. Sim 16:29, 6 March 2007 (UTC)

I assume you're talking about using factors like (4x − 3) in the construction of the Lagrange polynomial, instead of (x-\tfrac34) , in which case, I agree that it's better to do it the other way. Please go ahead and change it. -- Jitse Niesen (talk) 09:36, 7 March 2007 (UTC)


[edit] Errors

Any chance of a brief discussion of errors for Lagrange interpolation, preferably by someone who understands it properly (i.e., not me!)? me_and 21:21, 9 June 2007 (UTC)