OPT: update param for pca according to loco results
OPT: update param for pca according to loco results

Former-commit-id: 1c7107a45c79df37692a4006415710a965c229f4
Former-commit-id: 18e1fba62fd649117ae64bf5d1f15c56c392b129
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox