Experimental Physics and
Industrial Control System

Kay-Uwe Kasemir <[email protected]> · Fri, 01 Jul 2005 09:18:28 -0400

On Jun 30, 2005, at 20:37, Benjamin Franksen wrote:

Hi Kay,

I hope you don't mind I post this on the list.

Not at all. Sorry I forgot core talk again and simply hit 'reply'.

On Thursday 30 June 2005 17:47, you wrote:

On Jun 30, 2005, at 07:35, Benjamin Franksen wrote:

I don't yet see how we specify when 'user-defined fields' get
processed.

My proposal allows them to hook into the record's processing
at two points:
After getting the value (so the hook can modify the data),
and at the very end (so the hook can add averaging or FLNKs or ...).
That handles all the test cases which we had at the SLAC meeting.

..
o what if there is no 'value' (see a recent posting on core-talk, I
believe it was from Andrew)

Sure, there are records where adding a user-defined 'average'
field doesn't make sense.

But then with your more elaborate idea of replacing predefined
records with record building blocks, wouldn't you get the same
issue where some building blocks are simply not meant to be combined?

o what does smoothing do if the value exists but is an array. Or an
integral type. Or a string?

What should the calc record do if all its inputs are strings or arrays?
Again you have ample opportunity to create useless databases.
With user-defined fields, you could actually create
specific 'average' fields to determine the average length of a string
or the average value of elements in an array or ...,
just like your building blocks could offer similar pieces
which are meant to go only with scalar, array, string, ... records.

Thus, I argue for abandoning the idea to have per-instance defined
fields. Instead, ..... create a new record type.

....I'll try to present an example on the wiki.

I think that's very helpful. I like the general idea of
record building blocks, I just don't see an efficient way to get there.

Thanks,
-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System