OPT: maths: now checks if all input data have same size
OPT: maths: now checks if all input data have same size

Former-commit-id: 185ddee620724710051f711106f970dbd4f11279 [formerly 93a6ca2d3bb546e4b40379e0be95a2dd5bc3e6c2]
Former-commit-id: 094d5eb040910c6fd10f0cd3f6d16aae59e33cf7
Former-commit-id: 820e4be6468741956d97d65a712a3f0713aac0dc
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox