XxYxZ Statistic
This operator applies an XxYxZ statistic filter to the multibeam echogram.
You can define the statistic and the size of the window on the XxYxZ Statistic page of the Variable Properties dialog box.
Echoview accepts operands with the following data types:
 Multibeam magnitude
 Multibeam phase
 Multibeam Sv
 Multibeam TS
 Multibeam unspecified dB
This operator may be of use with edge detection, intermittent noise removal and other signal processing tasks.
Note: Under live viewing, the Live Export based on a convolution variable may be limited.
Settings
The XxYxZ Statistic Variable Properties dialog box pages include (common) Variable Properties pages and these operator pages:
Operands page
XxYxZ Statistic page
This page is used to specify the filter statistic and the size of the filter window (see Sliding window and kernel).
Setting 
Description 
Statistic 

Percentile (%) 
Specifies the Nth Percentile (0 to 100%). 
Rows (samples) 
An odd number between 1 and 999 specifying the number of rows (X) for the window. 
Columns (beams) 
An odd number between 1 and 999 specifying the number of columns (Y) for the window. 
Layers (pings) 
An odd number between 1 and 999 specifying the number of layers (Z) for the window. 
Input samples per calculation 
The number of values per calculation = Rows × Columns × Layers The larger the number, the longer it takes for the operator to execute. 
Algorithm
Available XxYxZ Statistic filter kernel algorithms.
Statistic 
Value 

Where:
Echoview computes the mean in the linear domain. 

The minimum of the values in the XxYxZ window.  
The maximum of the values in the XxYxZ window.  
The median of the values in the XxYxZ window. The median is the sample value of the 50th percentile.  
Percentile (%)  The Nth percentile score of the values in the XxYxZ window. yI, J (window) = Wk + (Wk+1  Wk) (k'  k)


See Mean above for the definition of n, xj and . Echoview computes the standard deviation of the values in the window in the linear domain. 

The variance s2. See Standard deviation above for the definition of s. Echoview computes the variance of the values in the window in the linear domain. 

See Mean above for the definition of n, xj and . Echoview computes the MAD of the values in window in the linear domain. 

See Standard deviation above for the definition of s and, Mean above for the definition of . Echoview computes the Cv of the values in the window in the linear domain. 

Where n, xj, s and are defined as above. For the Kurtosis calculation n > 3 is required to avoid an undefined division. Echoview computes the kurtosis of the values in window in the linear domain. The output is also a linear value. 
Notes:
 For details on how convolutions are applied in Echoview see Convolution algorithms: Convolution filter operators.
 The window shrinks as it approaches the edge of the data.
 Calculations for samples with dB values are carried out in the linear domain. Results that are unitless ratios are linear. Results that have units are generally converted back into the dB domain.