Error in LAPACK.geqrt3!

[bsxfan]

Julia's QR factorization calls the Linalg.LAPACK wrapper method:

function geqrt3!(A::StridedMatrix{$elty})

As far as I can see, all other the LAPACK wrappers do: chkstride1() on their arguments, but geqrt3!() for some reason does not. Can geqrt3!() somehow handle stride(::Submatrix,1)>1?. The following experiment suggests it cannot. I think geqrt3!() should also do chkstride1().

julia> B = sub(randn(4,2),1:2:3,1:2)
2x2 SubArray of 4x2 Float64 Array:
 -0.621393  -0.352925
 -1.0989     0.841417

julia> C = copy(B)
2x2 Float64 Array:
 -0.621393  -0.352925
 -1.0989     0.841417

julia> strides(B)
(2,4)

julia> strides(C)
(1,2)

julia> LinAlg.LAPACK.geqrt3!(B)
(
2x2 SubArray of 4x2 Float64 Array:
  0.956532  -0.538699
 -1.0989     0.841417,

2x2 Float64 Array:
 1.64963     0.0
 9.93473e44  0.0)

julia> LinAlg.LAPACK.geqrt3!(C)
(
2x2 Float64 Array:
 1.26243   -0.558711
 0.583338   0.721374,

2x2 Float64 Array:
 1.49222  0.0
 0.0      0.0)    

The factorizations differ.

In contrast, the other factorization methods do not accept B, e.g.:

julia> LinAlg.LAPACK.potrf!('U',B)
ERROR: LAPACK: Matrix must have contiguous columns

[andreasnoack]

The author of that wrapper forgot to write chkstride1. Fixed by a1f72e2