Cube merge and the history attribute

[Andrew Munslow]

Previous discussion: https://groups.google.com/forum/#!topic/scitools-iris/GC6PtNAgy60

I propose that cube merging ignore the content of the history attribute. The merged cube will be created with an empty history ready for the user to decide what history it should now carry.

Should an option be added to cube.merge() so that the user can choose one of the following:

• The history attribute is empty (default)
• The history attribute is filled with the concatenation of all the cube histories that went into the creation of the merged cube
• The history attribute from an identified cube (cube index?) is used (default to the first in the list)

Thoughts?

[Richard Hattersley]

Bill, Mark, Ed, Carwyn, and I had a MeatSpace chat this morning where we agreed in principle we needed to modify the handling of global attributes (of which "history" is one). Bill's due to post on that shortly so I won't go into detail, but for now it's just important to note the connection: what we decide to do with global attributes as a whole will modify/simplify the handling of "history" with respect to merge.

[LeonH]

There should be an option to have the history taken into account (not ignored) during merge as well, surely? I usually don't want it, but maybe it would be useful sometime?

Leon