GPA + PCA Error: Load landmark data failed

Support
1

Operating system: Mac OS 14.4.1
Slicer version: 5.6.2
Expected behavior: Generate GPA and PCA
Actual behavior: The following Error and warning messages:

QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object

QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object

QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object

QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object

AND then:

Load landmark data failed: Could not create an array from landmark files

I’m looking at 8 specimens I’ve landmarked using ALPACA. I’ve moved all the .mrk.json landmark files produced from running ALPACA into a single directory to run the GPA +PCA. I’ve examined the files briefly to make sure they have the same number of landmarks and they have all have 4066 pseudolandmarks. I’ve tried running GPA on only 2 or 3 specimens and get the same errors.

When I ran ALPACA, it took my computer several hours. Did I do something wrong when I ran ALPACA? I left scaling and projection unchecked. I’ve included an image of some of the specimens and landmarks. Thank you for your help. I am a SlicerMorph novice and appreciate any insight you can provide. Thanks.

Screenshot 2024-05-28 at 9.14.19 AM
Screenshot 2024-05-28 at 9.14.19 AM1174×1052 99.3 KB

2

If you can share the data we can take a look.

3

Thank you for your reply! I reran the analysis and used fewer landmarks (600 instead of 4k) and checked projection and scaling and now it works! I used the projected landmarks in the analysis. I think it was either number of landmarks I used or that I didn’t project or scale the data.

1 Like
4

Projecting the points can take a while for dense point clouds like this. Try the original without choosing the project points. The caveat it they may end up not on the surface of the target model.