Tony Garnock-Jones uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-tonyg.970.mcz

==================== Summary ====================

Name: Collections-tonyg.970
Author: tonyg
Time: 20 December 2021, 4:58:44.529376 pm
UUID: 518b67c7-1a4a-4b44-9ee6-8b4d9f5434a7
Ancestors: Collections-mt.969

Support transposition of nonrectangular matrices.

=============== Diff against Collections-mt.969 ===============

Item was changed:
  ----- Method: Matrix>>transposed (in category 'accessing rows/columns') -----
  transposed
+ 	^ self species rows: ncols columns: nrows tabulate: [:i :j | self at: j at: i]!
- 	self assert: [nrows = ncols].
- 	^self indicesCollect: [:row :column | self at: column at: row]!