statistics express vi

[DirkLV]

When using the statistics express vi in LV7.1, I get wrong results for standard deviation. I particular, the VI outputs the mean value instead, but only for certain data sets. Most of the times it works fine. I can not see any problem in this very simple VI. Any ideas?

Thanks

Dirk

[NIDave]

Its because in column 2, row 497 in that row you have non value. When it finds the stdev it cant count that so you deviate by your mean.

In case you need it your actual STDEV is .001125

Now you need to figure out why you got a non value for that measurement.
Hope this helps.
-Dave

[PauloM]

Hello Dirk,

I think you found a bug on the LabVIEW's statistical functions...
I removed that set of data from the array and tried the normal (not express) statistical functions and they return NaN and for the others it's ok!
See attached code.

Paulo

[PauloM]

Ups, didn't saw the NaÑ, sorry!

[DirkLV]

Thank you, folks. The reason that I just did not check for a NaN entry is that one would expect that the statistics function should return NaN or an error indication if this happens, isn't it?
Thanks again, Dave and Paulo.

Dirk