[Numpy-discussion] Re: quadrature.py vs Multipack

Jean-Bernard Addor jbaddor at physics.mcgill.ca
Thu Mar 23 11:00:44 EST 2000


Hey!

I am now able to reply to my question!

Quadpack from multipack is much more quicker and accurate!

and it needs not Python 1.5.2 (on my system it crashes with new python,
but it is a quick installation)

comparision:

>>> quadrature.quad(lambda t: t**(H-1), 0, 1)
2.54866576894
>>> quadpack.quad(lambda t: t**(H-1), 0, 1)
(3.33333333333, 4.26325641456e-14)
>>> 1/H 
3.33333333333

The expected result is 1/H, (H was .3).

It is possible to improve the precison of the result of quadrature, it
becomes very slow, but never very precise.

Jean-Bernard

On Wed, 22 Mar 2000, Jean-Bernard Addor wrote:

> Hey Numpy people!
> 
> I have to integrate functions like:
> 
> Int_0^1 (t*(t-1))**-(H/2) dt
> 
> or
> 
> Int_-1^1 1/abs(t)**(1-H) dt, with H around .3
> 
> I just tried quadrature on the 1st one: it needs very order of quadrature
> to be precise and is in that case slow.
> 
> Would it work better with Multipack?
> 
> (I have to upgrade to python 1.5.2 to try Multipack!)
> 
> Thank you for your help.
> 
> 	Jean-Bernard
> 
> 





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