***What is your favorite VI or other software to view large sets of waveform data?

[<Mike Ross> mross@smpcorp.com]

What is your favorite VI or other software to view large sets of
waveform data?

I have to look at waveforms with several sets of y data of 10000 or so
points. Should I put this into Excel? There are no cursors, or zoom
capabilities, and so on in Excel.

Using a graph in LV is very slow when loaded down with this much data.
Frankly a scope is easier for viewing waveforms. A scopelike utility
for Windows?

MathCAD?

Is there any neat shareware out there?

Thanks for your opinion,

Mike

[mikeporter]

There are a large number of analysis packages on the market that can display very large datasets. The one to choose depends largely on the nature of the data and what you want to do with it after you have loaded it in. Wandering down the software aisle at your local Staples you will find at least two or three.

With datsets the size you are contemplating, a major feature to look for is a zoom function that initially shows the entire waveform but lets you narrow in on the data you want to see.

DIGRESSION ALERT

Actually, this sort of algorithm isn't to hard to code. I wrote a viewer once that allowed you to view datasets of arbitrarily large size (in V3 I think... though it may have been in V4). The code initally presented an overview of the entire dataset
by decimating it down to a size that LV could display rapidly. As the user zoomed in using the cursors (not LV's graph zoom) the code would extract the selected portion of the data, redecimate it if necessary and redraw the display. (Which by the way is all the fancy packages really do anyway.)

The tricky part is selecting a decimation function that retains the overall shape of the data.

ENDOF DIGRESSION

Several years ago I wrote an article for a magazine (Personal Engineering and Instrumentation News) that dealt with graphing packages that could handle a million datapoints at that time (late eighties) there were over a dozen programs--and they were all better than Excel...

Mike...

[Philip_Courtois]

An obvious candidate for handling large datasets would be DIAdem. The current version (end of 2004) DIAdem 9.1 is capable of working with data files that contain over 100 billion data values.

Is 100.000.000.000 data points enough for your purpose?

Microsoft Excel 2003 can not handle more than 256 x 65536 = 16.777.216 data points. This means that DIAdem can handle datasets that are almost six thousand times larger than what is limited by Microsoft Excel.

More information about DIAdem here.