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zetafunc wrote:

These coefficients are part of a more general phenomenon called the Savitzky-Golay filter in numerical analysis. In fact the traditional five-point 'stencil' reads:where . You can derive this result simply by playing around with the Taylor series for with . It's a little tedious, but you can see the derivation here: https://en.wikipedia.org/wiki/Five-poin … he_formulaThere are analogous formulae for higher order derivatives too, and several published papers about the error term.

That is very informative, zeta. Thanks for the reply.

I wonder if there is a way to calculate the midpoint differentials by 4 points around it:

dy/dx ]x=0

ddy/dx/dx ]x=0

given y[-0.5], y[0.5], y[-1.5] & y[1.5]

**George,Y**- Replies: 2

I come across this method when trying to calculate the derivative of an unknown curve which I have only sample points at equal grids.

The simplest way to calculate numerical derivative is three-point formula:

dy/dx = (y[1]-y[-1]) /2/dx

ddy/dx/dx = (y[1]+y[-1]-2*y[0]) /dx/dx

But I found this one on five points :

dy/dx = ( y[-2] -8*y[-1] +8*y[1] -y[2]) / (12*dx)

ddy/dx/dx = (-y[-2] +16*y[-1] -30*y[0]+ 16*y[1] -y[2]) / (12*dx^2)

It is surprisingly accurate when I test the derivative on exp(3) using exp(2) exp(2.5) exp(3) exp(3.5) exp(4)

the result of 1st numerical derivative and 2nd are

20.04243 & 20.07127

remember the correct answer are both exp(3) = 20.08554

Can anyone prove how this works?

4th polynomial?

Or Kuran online university

Today's textbooks are very concise, and you can learn most topics up to undergraduate level on your own

Note the common ratio is a complex number.

Uh it is surprising to find so many mathematicians practice meditation!

Happy New Year!

AX = X diag( 入i )

V := X^(-1)

AX diag( 1/ 入i )V = X diag( 入i )diag( 1/ 入i ) V = I

thus

A^(-1) = X diag( 1/ 入i ) X^(-1)

I believe you should use some web based GUI to ease the visit of your application.

Try JavaScript.

bobbym wrote:

Doesn't that have two parameters not one? That is why I asked.

Normsdist in Microsoft Excel

bobbym wrote:

Hi;

What is N?

Normal Probability Distribution Function

bobbym wrote:

Hi;

I do not think those are doable.

Yes, they are. Recall Normal probability distribution, please.

bobbym wrote:

Hi;

What is d?

d is the differential operator

After this change of variable, I think now the question is easier.

Sorry guys, I made a mistake, the question should be:

bobbym wrote:

A different integration?

I have found a way to integrate this directly, but it is very tricky.

There actually is closed form, but through a different integration.

Oops, I post the wrong question

Look at this poster before 2013 Asian Football Championship, the score will be 3:0

Let me explain conditional statement via set arguments.

If you know A is true for sure, and you can immediately infer that B is true.

A is true is sufficient condition that B is true.

We can also say that the event A is true is contained in the event B is true.

Like you are in London implies that you are in UK. But the other way around is not necessarily true.

and we can say B is necessary condition for A, for notB is in notA - you are not in UK so you are not in London.

Hope this theory make your logic class a lot easier!

anyone?

Alright guys, I think I should give up.