Variance for a set of real time data

[Chathuri]

Hi,

I am continuously acquiring a set of sensor data through LABVIEW with a sampling rate of 100Hz (100samples per sec). What I want to do is to find the variance of the set of data every 0.1s. Im collecting the acquired sensor data into a 1D array "SensorData." Then wat I want to do is each time 10 new samples are collected, I want to find the variance. I tried using the variance ptbypt but it always outputs a value 0.0

Your help is greatly appreciated.

Thanks!

Chathuri 

[Vsh · Accepted solution]

What is the sample length you specified in Variance PtbyPt vi? Did you check the initialize condition?

How exactly you are calling this subVI?. To get a variance output of 0.1 second, you might want to set your sample lenght to 10.

Could you post a VI which shows this value?

If you are seeing 0.0, try to expand you numeric indicator, there might be an exponential value at the end 

[Chathuri]

Yes, I feel so stupid. I left the indicator to display values of 2 decimal places. I increased the significant digits and now I am getting a value 🙂 Thankyou!

Chathuri

[Vsh]

And I thought I solved your problem. 

[Chathuri]

🙂

[Vsh]

Oh I was right!!