comp.lang.idl-pvwave archive
Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Home » Public Forums » archive » Error Bar Thoughts
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend  		Return to the default flat view Create a new topic Submit Reply
Re: Error Bar Thoughts [message #74854 is a reply to message #74769] Wed, 02 February 2011 13:26 Go to previous messageGo to previous message
wlandsman is currently offline  wlandsman
Messages: 743
Registered: June 2000
Senior Member
On Wednesday, February 2, 2011 12:50:24 PM UTC-5, David Fanning wrote:

> to specify the location of the high and low locations
> of the bar? As an offset from the data point?

For what it is worth, the ITTVIS supplied procedure PLOTERR specifies the error as an offset from the data point, but the ITTVIS supplied ERRPLOT wants the low and high values. In my own work, errors are nearly always suplied as a offset (e.g. Poisson errors are a square root of the counts). Note that users often want to display X along with Y error bars.

The two most difficult parts of writing my own PLOTERROR ( http://idlastro.gsfc.nasa.gov/ftp/pro/plot/ploterror.pro ) were handling the X/YLOG and NSUM keywords to PLOT. You don't want the entire logarithmic plot to abort because one of the error bars extends to negative numbers, and you want to appropriately reduce the size of the error bars when summing data together. ---Wane

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Re: IDL 8 image function
Next Topic: Re: Coyote Graphics Update, Wed 2 Feb

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Sun Nov 30 06:11:55 PST 2025

Total time taken to generate the page: 1.76207 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.0.7.
Copyright ©2001-2013 FUDforum Bulletin Board Software