added vcat and hcat for two LinearOperators and testing.

[lruthotto]

No description provided.

[coveralls]

Coverage increased (+2.04%) to 62.63% when pulling 7979c4b on lruthotto:master into fb7e5b2 on dpo:master.

[coveralls]

Coverage increased (+2.04%) to 62.63% when pulling 7979c4b on lruthotto:master into fb7e5b2 on dpo:master.

[dpo]

Many thanks! hcat and vcat have been on my list for a while. I really want to pull this but I have a few comments (I will also insert some in the code). Would you mind trying to imitate the coding style of the rest of the module? In particular:

• two spaces for indentation
• a space after a comma in an argument list (function declaration or call)
• spaces around ::

I know that that doesn't quite correspond to Base Julia, but I find it's more readable. Sorry for nitpicking.

[dpo]

Other operations with operators use promote_type() to infer the smallest common type that can represent all operands. It would be best to do the same here.

[dpo]

Could we generalize this to an arbitrary number of arguments? Something like

function hcat(ops...)
  nrow = ops[1].nrow;
  op0 = opZeros(nrow, 0, dtype=typeof(ops[1]));  # Dummy operator to begin concatenating.
  for (i, op) in enumerate(ops)
    op0 = [op0 , op];
  end
  return op0
end

(untested)

[lruthotto]

Thanks for your comments, @dpo. See revised version now.

[coveralls]

Coverage increased (+4.21%) to 64.8% when pulling 1b8faa6 on lruthotto:master into fb7e5b2 on dpo:master.

[coveralls]

Coverage increased (+4.21%) to 64.8% when pulling 1b8faa6 on lruthotto:master into fb7e5b2 on dpo:master.

[dpo]

Many thanks! This is great.