Problem 2585. How to reverse spdiags?

Jean-Marie Sainthillier

44 solvers

2 likes

Solve

Solve Later

The spdiags function extracts all nonzero diagonals from the m-by-n matrix A.
So if
  A = [1 2 3;4 5 6;7 8 9]
then
  spdiags(A) = [7 4 1 0 0;
                0 8 5 2 0;
                0 0 9 6 3]
But if I give you spdiags(A), can you give me A ?

Solve

Solution Stats

278 Solutions

44 Solvers

Last Solution submitted on Sep 28, 2026

Last 200 Solutions

Problem Comments

1 Comment

Paul Berglund on 5 Oct 2014

% this problem is not guaranteed solvable
isequal(spdiags([eye(5) zeros(5)]),spdiags(eye(5)))

Solution Comments

Show comments

Problem Recent Solvers44

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!