Class: Statkit::Spec::StdevFuncExp
- Defined in:
- lib/statkit/specexp.rb
Instance Method Summary collapse
- #add_input_chunk(input_chunk) ⇒ Object
- #evaluate ⇒ Object
-
#initialize ⇒ StdevFuncExp
constructor
A new instance of StdevFuncExp.
- #streaming? ⇒ Boolean
Methods inherited from BaseExp
Constructor Details
#initialize ⇒ StdevFuncExp
Returns a new instance of StdevFuncExp.
48 49 50 51 52 |
# File 'lib/statkit/specexp.rb', line 48 def initialize @nr_input = 0 @sum = 0 @sum_sq = 0 end |
Instance Method Details
#add_input_chunk(input_chunk) ⇒ Object
58 59 60 61 62 63 64 |
# File 'lib/statkit/specexp.rb', line 58 def add_input_chunk(input_chunk) input_chunk.each do |val| @nr_input += 1 @sum += val @sum_sq += val ** 2 end end |
#evaluate ⇒ Object
66 67 68 69 |
# File 'lib/statkit/specexp.rb', line 66 def evaluate() var = @sum_sq / @nr_input.to_f - (@sum / @nr_input.to_f)**2 Math.sqrt(var) * Math.sqrt(@nr_input / (@nr_input.to_f - 1)) end |
#streaming? ⇒ Boolean
54 55 56 |
# File 'lib/statkit/specexp.rb', line 54 def streaming? true end |