Subject: Array Wish list From: "Jack Hamilton" <[EMAIL PROTECTED]> Date: Mon, 19 Jan 2004 21:23:15 -0800
>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. 1) That orientation does have some advantages in certain types of operations. It is just not the way we are usually used to look at two dimensional data. 2) Transposing in the graph itself is absolutely no extra effort besides of very, very maybe an additional addition in the index calculation. You need to read the data anyhow and if you do that row by row or column by column makes no real difference. >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. Well if he would have fixed it there would be a transpose every time multi channel data comes from the DAQ card, because that is the way the data comes from the DAC. At those times with a 486 33MHz CPU transposing data was very costly in terms of CPU cycles and also in terms of memory (most computers had to run Windows 3.1, and LabVIEW with its 32 bit subsystem on 8MB or less) and letting the graph do the correct indexing when displaying data made all the difference about being able to acquire 100kS per seconds AND display it on the screen in real time. You wouldn't have been happy then either when a guy at NI had said: just wait 5 years from now and you will be able to do it then, no matter of the inherent transpose overhead, because 500MHz Pentiums with 128 MB of RAM will be standard commodity by that time. Rolf Kalbermatter CIT Engineering Nederland BV tel: +31 (070) 415 9190 Treubstraat 7H fax: +31 (070) 415 9191 2288 EG Rijswijk http://www.citengineering.com Netherlands mailto:[EMAIL PROTECTED]
