Class: Bmg::Summarizer::DistinctCount

Inherits:
Bmg::Summarizer show all
Defined in:
lib/bmg/summarizer/distinct_count.rb

Overview

Collect the count of distinct values.

Example:

# direct ruby usage
Bmg::Summarizer.distinct_count(:qty).summarize(...)

Instance Attribute Summary

Attributes inherited from Bmg::Summarizer

#functor, #options

Instance Method Summary collapse

Methods inherited from Bmg::Summarizer

avg, by_proc, collect, concat, count, distinct, distinct_count, first, #happens, #initialize, last, max, median, median_cont, median_disc, min, multiple, percentile, percentile_cont, percentile_disc, stddev, sum, summarization, #summarize, #to_summarizer_name, value_by, variance

Constructor Details

This class inherits a constructor from Bmg::Summarizer

Instance Method Details

#_happens(memo, val) ⇒ Object

Adds val to the memo array



19
20
21
22
 
# File 'lib/bmg/summarizer/distinct_count.rb', line 19

def _happens(memo, val)
  memo[val] = true
  memo
end

#finalize(memo) ⇒ Object 



24
25
26
 
# File 'lib/bmg/summarizer/distinct_count.rb', line 24

def finalize(memo)
  memo.keys.size
end

#least ⇒ Object

Returns [] as least value.



14
15
16
 
# File 'lib/bmg/summarizer/distinct_count.rb', line 14

def least()
  {}
end