# MathMean

Calculates the mean (first moment) of array elements. Analog of the [mean()](https://stat.ethz.ch/R-manual/R-devel/library/base/html/mean.html) in R.

```
double  MathMean(
   const double&  array[]                // array with data
   );

```

Parameters

array

[in]  Array with data for calculation of the mean.

start=0

[in]  Initial index for calculation.

count=WHOLE_ARRAY

[in]  The number of elements for calculation.

Return Value

The mean of array elements. In case of error it returns [NaN](/en/docs/basis/types/double) (not a number).