[VoxBo] trial averages in vbview

[Charan Ranganath, Ph.D.]

Dear Dan and team voxbo, I was wondering if there's been any progress on 
the two points below (erroneous fitted values and quirks with handling 
trials with averaging windows that exceed the length of a scanning run).

Thanks, and happy holidays, CR.

Charan Ranganath wrote:
> Oops sorry, I hit send too soon. Here it goes again:
>  Dear Dan and team voxbo, 
> the new version of vbview is much improved, so we have been pushing it to
> the limit. Here are some things we've noticed which I wanted to alert you to:  
> (1) plotting of the fitted values seems to be messed up. The values that I
> get in vbview look totally different than what I've gotten in the old voxel
> surfer. The voxel surfer fits look more reasonable, so I trust them. 
> 
> (2) the trial averaging produces slightly different results between VBview
> and voxel surfer. To compare, we averaged the data from a masked region in
> both the idl viewer and vbview. I'm attaching a file that has both time
> series in it. As you can see, the averages are slightly different. The
> differences are much more apparent if you set the averaging window to be 10
> images (not shown). I have 2 hypotheses about the problem, which are not
> mutually exclusive:
> (A) When the averaging window exceeds the number of images that follow a
> particular event, the idl program excludes those trials. VBView may be
> including those trials--I guess this because when I set the averaging
> window to 10, the idl viewer tells me it has 19 trials, whereas vbview
> tells me it has "20 trials (or whatever)". If I am correct, this  leads to
> the question of what the program does to account for the missing data points. 
> (B) It may be the case that vbview and the idl viewer each have a slightly
> different way of removing covariates of no interest from the time series
> data. This could explain the slight variations even when averaging a
> smaller # of time points (i.e., such that the same number of trials was
> shown for both the idl viewer and vbview).
> 
> Let me know what you think. Thanks! CR 
>  
> 
> 
> ------------------------------------------------------------------------
> 
> ;VB98
> ;REF1
> ;
> ; time series pulled from pixel surfer
> ; DateCreated: Tue_Nov__7_06:21:23_2006
> ; SourceMatrix:	/data5/mita_data/f_h_exp/sm_041802_NEW/epi/voxbo_analys/exp_sm/voxbo_analys
> ; SelectedPoint:	38	22	5
> 
>   -0.00309445
>   -0.00296953
>  -0.000628260
>    0.00330820
>    0.00169909
> 
> ;VB98
> ;REF1
> -0.00309446
> -0.00296953
> -0.000628288
> 0.00330817
> 0.00169907