Subsetting averages in Osprey to segment data

Analysis / Modeling
1

hi, I want to subset the number of averages in a Hercules dataset total n = 720 ave) so that the first 320 averages are ‘part 1’ and the second 400 are ‘part2’ because the subject transitioned into sleep in the second part of the scan. Is it valid to split the scan timepoints into 2 parts?

if so, is it ok to edit the io_loadspec_twix code in osprey to load only certain timepoints in at time? it appears to be working & I am making sure that the fids_A index starts on the correct index but I’m not sure if this could mess anything up.

my edits to io_loadsepc_twix
fids = fids(:,:,my_index); %my edited line where my_index = 1:320 or 321:720

regular code:
if strcmp(seq, ‘HERMES’ ) || strcmp(seq, ‘HERCULES’)
if size(fids, 3) > 1
fids_A = fids(:,:,1:4:end)
fids_B = fids(:,:,2:4:end)

2

Hi @sdw,

Thanks for reaching out.

From what I can infer from the code snippets that you have posted I’d say that it works fine. Did you test if the downstream modules, especially, OspreyProcess work fine including the plots?

I am asking, because these modules rely on the rawAverages numbers and averages in the struct which would not be correct if you split the data.

Best,
Helge