[Octave-bug-tracker] [bug #62277] QR needs to accept "econ" argument for Matlab compatibility

[Markus Mützel]

Follow-up Comment #3, bug #62277 (project octave):

>From the documentation of `qr`:
> If the final argument is the scalar 0 an "economy" factorization is
returned. If the original matrix A has size MxN and M > N, then the "economy"
factorization will calculate just N rows in R and N columns in Q and omit the
zeros in R. If M ≤ N, there is no difference between the economy and
standard factorizations. When calculating an "economy" factorization and A is
dense, the output P is always a vector rather than a matrix. If A is sparse,
output P is a sparse permutation matrix. 
> Background: The QR factorization has applications in the solution of least
squares problems 
> min norm (A*x - b) 
> for overdetermined systems of equations (i.e., A is a tall, thin matrix). 
> The permuted QR factorization [Q, R, P] = qr (A) allows the construction of
an orthogonal basis of span (A). 

Is that what you were referring to?



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