Reflects assumptions about streamlines fix recommended (and incoming)

[DanNBullock]

mba/compute/mbaComputeFiberLengthDistribution.m

Line 30 in 1f06c4b

Lmm = cellfun('length',fg.fibers);

This computation assumes that (1) the nodes of streamlines are always 1mm spaced and (2) evenly spaced (such that each internode difference is equivalent).

Currently it is simply returning the number of nodes in all streamlines in an fg.

This is particularly a problem due to:

mba/compute/mbaRemoveFibersCoordsDistributionOutlier.m

Line 31 in 1f06c4b

if notDefined('numberOfNodes'), numberOfNodes=100; end

if notDefined('numberOfNodes'), numberOfNodes=100; end

which resamples all streamlines to the same number of nodes

Recommended fix:

streamsTotal=fg.fibers;
Lmm =[];
for istreamlines=1:length(fg.fibers)
Lmm(istreamlines)=sum(sqrt(sum(diff(streamsTotal{istreamlines},1,2).^2)));
end

(or some cellfun variant thereof to avoid the streamsTotal reassignment)

[francopestilli]

@DanNBullock sounds good slower but geenral can you please make a pull request?
I accepted your previous pull, so update the repo.

[DanNBullock]

ok, I should probably test it first though, will do that and then make request

[francopestilli]

yes pls
happy to test on my side too

[DanNBullock]

resolved: #17

[DanNBullock]

Interesting epilogue to this story:

Apparently a similar issue was also included in MRtrix for a while:

MRtrix3/mrtrix3@bbfdaea

But then they ended up getting a publication out of fixing it:

https://www.sciencedirect.com/science/article/pii/S105381192200859X