# Region Statistic

This operator is used to fill the data points in matching regions with a statistic calculated on the first operand for those regions. Echoview currently supports mean, maximum, minimum and standard deviation statistics for this operator.

Data points in overlapping matching regions will be assigned a 'no data' value, as will all data points outside of regions if the standard deviation statistic is chosen. See also Wideband frequency response considerations.

Echoview accepts a single operand of the following data types as input:

- Complex power dB
- Complex Sv
- Complex TS
- Power dB
- Pulse compressed complex power dB
- Pulse compressed complex Sv
- Pulse compressed complex TS
- Sv
- TS
- Unspecified dB

**Note:** The Region statistic operator uses analysis regions and fish track regions.

## Settings

The Region Statistic Variable Properties dialog box pages include (common) Variable Properties pages and these operator pages:

### Operands page

### Region Statistic page

Settings |
Description |

Region class |
Choose one or all region classes to apply the statistic. |

Statistic to calculate |
Select the statistic to be calculated for the selected region class. You can choose from one of: - Minimum
- Mean
- Maximum
- Standard Deviation
All will produce a virtual variable of the same data type as the operand. The choice of standard deviation will result in a linear variable which with all samples outside of regions receiving the no data value. The Mean calculation is carried out in the linear domain, then converted to dB. |

**Note:** The selected region class will remain visible at all times.