Module datafusion_functions_aggregate::variance

VarianceSample: variance sample aggregations. VariancePopulation: variance population aggregations.

Structs

• VarianceAccumulator
  An accumulator to compute variance The algorithm used is an online implementation and numerically stable. It is based on this paper: Welford, B. P. (1962). “Note on a method for calculating corrected sums of squares and products”. Technometrics. 4 (3): 419–420. doi:10.2307/1266577. JSTOR 1266577.
• VarianceGroupsAccumulator
• VariancePopulation
• VarianceSample

Functions

• var_pop
  Computes the population variance.
• var_pop_udaf
  AggregateFunction that returns a AggregateUDF for VariancePopulation
• var_samp_udaf
  AggregateFunction that returns a AggregateUDF for VarianceSample
• var_sample
  Computes the sample variance.