# $$\text{StdDev}$$¶

You can use the $$\text{StdDev}$$ function to calculate the standard deviation of a collection of basic values. Values can be provided as parameters or contained within a collection of iterable types.

You can use the \stddev backslash command to insert this function.

The following variants of this function are available:

• $$\text{real } \text{StdDev} \left ( \ldots \right )$$

This function calculates the standard deviation without Bessel’s correction using the relationship:

$\text{StdDev} \left ( X \right ) = \sqrt{ \frac{1}{N} \sum_{x \in X} \left ( x - \mu \right ) ^ 2 }$

Note that, like the $$\text{Count}$$ and $$\text{Average}$$ function, you can use this function to traverse complex data structures to calculate the standard deviation.

Figure 206 shows the basic use of the $$\text{StdDev}$$ function.

Figure 206 Example Use Of The StdDev Function