Matrix aggregations

Matrix aggregations is a family of functions, which is still being developed to provide a way to manipulate multiple fields at the same time and generate results for the fields in a matrix form. Matrix stats is the only type supported in matrix aggregations since version 5.0.

Matrix stats

This aggregation computes the numeric statistics on a set of given document fields, as shown in the following table:

Statistics measure	Description
count	The number of samples measured.
mean	The average value of the field measured from the sample.
variance	How far the values of the field measured are spread out from its mean value. The larger the variance, the more spread from its mean value.
skewness	This...