comp.lang.idl-pvwave archive: archive

Home » Public Forums » archive » QSIMP function

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: QSIMP function [message #85832 is a reply to message #85831]

Thu, 12 September 2013 10:05

wlandsman
Messages: 743
Registered: June 2000

Senior Member

One suggestion for improved accuracy is to interpolate your function at the midpoints of all your tabulated X values. You can use one of the options (e.g. spline,least-squares quadratic) in the INTERPOL() function without needing a loop. Then redo your trapezoidal integration routines but using twice as many points, then rebin your final answer by a factor of two.

On Thursday, September 12, 2013 11:58:40 AM UTC-4, fd_...@mail.com wrote:
>> So you don't want the area under a curve, but you want to get the area (estimated by a trapezoid) covered by consecutive points. Then the code you posted earlier is fine.
>
>
>
> The code for trapezoidal that I posted earlier it does not work very well, I have an underestimation because my data changes fast. That is why I am looking for an alternative method.
>
>
>
>> I presume you have millions of points if you are worried about using a FOR loop.
>
>
>
> Yeah because it takes me long time with a FOR loop.

Report message to a moderator

[Message index]

		QSIMP function By: fd_luni on Thu, 12 September 2013 06:31
		Re: QSIMP function By: wlandsman on Thu, 12 September 2013 07:56
		Re: QSIMP function By: fd_luni on Thu, 12 September 2013 08:40
		Re: QSIMP function By: wlandsman on Thu, 12 September 2013 08:49
		Re: QSIMP function By: fd_luni on Thu, 12 September 2013 08:58
		Re: QSIMP function By: wlandsman on Thu, 12 September 2013 10:05
		Re: QSIMP function By: fd_luni on Thu, 12 September 2013 11:01
		Re: QSIMP function By: Craig Markwardt on Fri, 13 September 2013 22:44
		Re: QSIMP function By: wlandsman on Sat, 14 September 2013 19:58

Previous Topic:	Widget programing - Please help!
Next Topic:	The IDL library for Shuffled Complex Evolution (SCEUA)

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 12:33:47 PDT 2025

Total time taken to generate the page: 0.40358 seconds