[Numpy-discussion] how to build a series of arrays as I go?

[Alexander Michael]

On Tue, Mar 18, 2008 at 5:27 AM, Chris Withers <chris@simplistix.co.uk> wrote:
> Travis E. Oliphant wrote:
>  > Generally, arrays are not efficiently re-sized.  It is best to
>  > pre-allocate, or simply create a list by appending and then convert to
>  > an array after the fact as you have done.
>
>  True, although that feels like iterating over the data twice for no
>  reason, which feels a bit weird.
>
>  In my case, I want to create a masked array, it would be nice to be able
>  to do that straight from a list, rather than having to turn the list
>  into an array and then turning the array into a masked array.
>
>  If I'm off base on this, let me know :-)
>
>  cheers,
>
>  Chris

Be default (if I understand correctly) the passing a regular array to
MaskedArray will not copy it, so it less redundant than it may at
first appear. The MaskedArray provides as masked *view* of the
underlying array data you give it.