[Ifeffit] Importance and Edge Step

[Bruce Ravel]

On Thursday 02 June 2005 13:06, Barton, David (DG) wrote:
> I noticed two new features in Athena 0.8.040 and am unsure of how to use
> them.  The new features are "Importance" and "Edge Step".  I attempted to
> use the Edge Step feature by checking "Fix Step" and then entering a value,
> but the Edge Step always reverts back to the automated value.  However,
> when I use the Increase/Decrease buttons (Left/Right arrow in Edge Step
> window) the edge step does change, but it only changes in increments of
> 0.01 which is much too large for my datasets.  Is there something I am
> missing here?
>
> Also, I couldn't locate Bruce's changelog for Athena so I am unsure of what
> the new "Importance" feature does.  Anyone used this new feature yet?


Importance:
  This number is used only in a merge and only when the "Weight by importance"   
  button in the Merge menu is checked.  It's intention is to allow 
  user-specified weights in a merge.  If you trust one data set twice as much 
  as another, the more trusted one might be given an importance of 2 while the 
  other is given an importance of 1.  This was in response to a feature 
  request -- personally I am not clear how would know how to weight different
  data sets. 

Edge step:
  I got a request for a quick way to play around with the size of the edge 
  step.  When the "fix step" button is checked, you can then specify an edge 
  step which will then be used to normalize the data.  You can type in a 
  number, as before, or you can tweak the edge step up or down.  You can set  
  the size of the tweak in the preferences using bkg->step_increment.  Note 
  that if the "fix step" button is not checked, the edge step will be 
  recomputed every time the background is recalculated.

And I do need to be more conscientious about updating the change logs.  Sorry.

B

-- 
 Bruce Ravel  ----------------------------------- bravel at anl.gov  -or-
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