Get Standard Deviation of a Signal

[virus86]

How would I get the standard deviation of a signal?

[GerdW]

Hi virus,

you already calculate the SD somewhere in the lower half of the block diagram. What else do you want to know?

There's a 2nd function to calc the stddev in the math palette -> prob & stats. It uses an input array...

[virus86]

I dont think my pogram works. When I input a square wave and use my simple SD program with the Point to Point VI, the SD is zero. Then I tried the one in the math pallette, and the values are erratic.

I think I have to model the equation here (Standard Deviation of a signal) in Equation 2-2.

I attached a very simple signal SD VI, but it doesnt work.

[GerdW]

Hi virus86,

when I input a square wave I get non-zero results. And I get the same result by using PtByPt or standard function... (The PtByPt output is somewhat interesting though.)

In the context help of the stddev function you will find the same formula given as you linked in your last post - no need to recode

Run my attachment!