#### 22.7 Coefficient of Variation

The connection function coefficient of variation calculates the coefficient of variation
for each unit over more than one selected file acccording to the formula.
The coefficient of variation is the ratio betweeen standard deviation and
mean.

| (10) |

NODATA values are excluded from the calculation.

This statistic is often preferrable to standard deviation as a measurement of index
variability since higher index values are commonly associated with a higher deviation
from its mean. This effect is adjusted by deviding the standard deviation by the
mean value.