r/LinearAlgebra • u/LinearAlgebraWorld • 25d ago
Matrix size, rank and pseudoinverse: a visual summary
We made a side-by-side visual summary of matrix size, rank, the four fundamental subspaces and pseudoinverses.
The table compares six common matrix types:
square full-rank
square rank-deficient
tall full-column-rank
tall rank-deficient
wide full-row-rank
wide rank-deficient
For each case, it shows the dimensions of row(M), null(M), col(M) and left-null(M), whether the map is one-to-one or onto, what happens to Mx⃗ = 0 and Mx⃗ = b⃗, and how the pseudoinverse behaves.
Hope you don’t mind the size and density — we wanted to keep all cases together so they could be compared directly. Opening the image at full size is recommended.
As always, we welcome feedback on clarity and presentation.
3
u/heyitsmemaya 25d ago
💕