Standard Deviation Function missing in Ignition V8.1

In one of our projects we're using stdDev function to calculate the standard deviation.Recently We've Upgraded the Ignition version from 7.5 to 8.1.In 8.1version we found the StdDev function is missing form the Math Library. It seems the new function system.math.standardDeviation is used in the latest version is there is any way to use the old function stdDev

Are you talking about an expression or scripting? Can you provide an example of what was previously working but now does not?

7.5 was a while ago. Were you by chance using this?