| Re: meanclip [message #82316] |
Thu, 06 December 2012 08:15 |
wlandsman
Messages: 743
Registered: June 2000
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Senior Member |
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meanclip.pro, is not a standard IDL procedure but in the IDL Astronomy library ( http://idlastro.gsfc.nasa.gov/ftp/pro/math/meanclip.pro ).
As David said, you don't give enough information, but I am going to guess that
the first column in your array contains your X values, and the second column contains the Y values you want to plot. If true, then I would copy these into X and Y vectors to make it easier to keep track of things.
IDL> x = arr[*,0]
IDL> y = arr[*,1]
IDL> help,arr,x,y
ARR DOUBLE = Array[1439, 2]
X DOUBLE = Array[1439]
Y DOUBLE = Array[1439]
MEANCLIP is meant to take the mean of an array after iteratively removing outliers, but it also has a keyword to find "good" subscripts -- by default those values within 3 sigma of the mean.
IDL> meanclip,y,arrmean,subs=subs
IDL> help,subs
SUBS LONG = Array[1435]
So meanclip has thrown out 4 outliers. Now one can plot only the good data
IDL> cgplot, x[subs], y[subs]
--Wayne
On Thursday, December 6, 2012 6:13:48 AM UTC-5, Charlie Paul D'auria wrote:
> Hi everyone.
>
>
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> I was just wondering if anyone can guide me in using meanclip.pro? I'm am an IDL beginner and the online documentation is sparse.. (I don't get it)
>
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> I have a double array of 2 columns and 1439 rows.
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>
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> I'd like to use this program to clip data that is a certain amount of sigma away from the last value and then plot it. I am also using the Poly fit routine if this is relevant.
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> Any help would be great appreciated!
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> Charlie
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| Re: meanclip [message #82317 is a reply to message #82316] |
Thu, 06 December 2012 06:04  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Charlie Paul D'auria writes:
> I was just wondering if anyone can guide me in using meanclip.pro? I'm am an IDL beginner and the online documentation is sparse.. (I don't get it)
>
> I have a double array of 2 columns and 1439 rows.
>
> I'd like to use this program to clip data that is a certain amount of sigma away from the last value and then plot it. I am also using the Poly fit routine if this is relevant.
I think you are going to have to give us more clues
about what you are trying to do. Does your two column
array represent point locations? What does "away"
mean in the context you are using it? Which one
of these points in your array is the "last value"?
Why do you think PolyFit might be relevant?
Too many questions to even begin to formulate an answer! ;-)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thue. ("Perhaps thou speakest truth.")
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