As far as I've ever heard, the transpose arrays don't use any extra
memory. The transpose function is done "in place". I'm sure a few extra
bytes are needed for temporary storage, but supposedly the same array
buffer is reused. I would guess that the graph transpose option is also
not a memory hog.
The way the data comes from the DAQ vis is probably the most sensible
way. It's actually good in that if you want to combine the output of
two or more successive calls to AI Read, you can just concatenate the
arrays.
If you think of how a labview 2D array is stored in memory (row data
lies together), and how a DAQ scan card has to store it's data (data
from a single scan lies together) then the current order makes a lot of
sense. lvdaq.dll would have to transpose the data in order to give it
to you in the other format. It may not take memory, but it's probably a
waste of time.
I'd rather keep control of when the transposes happen rather than have
the computer assume I always need it done. That's such a Microsoft
approach ("why would you want to see any DLLs in the Windows Explorer?
I'll just hide them." or everyone's favorite: "It looks like you're
writing a letter...")
Jason Dunham, President
SF Industrial Software, Inc.
415 743 9350 x142
[EMAIL PROTECTED]
-----Original Message-----
From: Jack Hamilton [mailto:[EMAIL PROTECTED]
Sent: Monday, January 19, 2004 9:23 PM
To: LabVIEW -Info; [EMAIL PROTECTED]
Subject: Array Wish list
I wish they would fix the orientation of the array that comes from the
analog DAQ functions.
All the arrays are transposed wrong and you have to transpose them to
even
plot them (yes, yes you can select the plot to 'transpose') Transposing
is
memory intensive no matter how you do it.
Hopefully, the guy at NI who programmed this initially - still winces
when
he goes to sleep at night - He did not fix then - so now the other
1,000's
of us have to - every time.
Hey, don't fix it now!!!
Jack Hamilton
Hamilton Design
[EMAIL PROTECTED]
www.Labuseful.com
714-839-6375 Office
