Bitcoin Forum
June 25, 2018, 12:39:31 PM *
News: Latest stable version of Bitcoin Core: 0.16.1  [Torrent]. (New!)
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: Stats question (re: Fisher Transforms and Spatial Smoothing)  (Read 718 times)
bb113
Hero Member
*****
Offline Offline

Activity: 728
Merit: 500


View Profile
July 19, 2012, 03:20:40 AM
 #1

People here have been helpful in the past with questions like this, and I have spent all day trying to figure out what to do but could find no answer.

I have a matrix of pearson's R data that I wished to smooth using a gaussian kernal and use to generate Z-scores from which I will then determine a region of interest. The smoothing does improve the signal to noise ratio but I think the z-scores are being suppressed due to the smoothing process. When I perform the fisher transform (ie R->Z conversion) on the smoothed data the standard deviation is less than what would be expected from a set of pearson's R values, which I think may be invalidating the Z-scores. My solution was to "adjust" the Z scores of the smoothed data by multiplying every value of the matrix by the ratio of stdev(Data)/stdev(SmoothedData)... where stdev=standard deviation.

The result can be seen in the lower left panel, blue curves are just there for reference:



Am I doing something wrong here?
1529930371
Hero Member
*
Offline Offline

Posts: 1529930371

View Profile Personal Message (Offline)

Ignore
1529930371
Reply with quote  #2

1529930371
Report to moderator
1529930371
Hero Member
*
Offline Offline

Posts: 1529930371

View Profile Personal Message (Offline)

Ignore
1529930371
Reply with quote  #2

1529930371
Report to moderator
1529930371
Hero Member
*
Offline Offline

Posts: 1529930371

View Profile Personal Message (Offline)

Ignore
1529930371
Reply with quote  #2

1529930371
Report to moderator
Make sure you back up your wallet regularly! Unlike a bank account, nobody can help you if you lose access to your BTC.
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1529930371
Hero Member
*
Offline Offline

Posts: 1529930371

View Profile Personal Message (Offline)

Ignore
1529930371
Reply with quote  #2

1529930371
Report to moderator
1529930371
Hero Member
*
Offline Offline

Posts: 1529930371

View Profile Personal Message (Offline)

Ignore
1529930371
Reply with quote  #2

1529930371
Report to moderator
bb113
Hero Member
*****
Offline Offline

Activity: 728
Merit: 500


View Profile
July 19, 2012, 06:19:51 PM
 #2

Well I'm gunna go ahead and do it. If anyone questions it I'll just say it got the bitcoin forum stamp of silent approval.
Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!