Class: Array
- Includes:
- Statsample::VectorShorthands
- Defined in:
- lib/statsample.rb,
lib/statsample/vector.rb,
lib/statsample/dataset.rb
Instance Method Summary collapse
- #mean ⇒ Object
-
#prefix(s) ⇒ Object
:nodoc:.
-
#sd ⇒ Object
Calculate sample standard deviation.
-
#suffix(s) ⇒ Object
:nodoc:.
- #sum ⇒ Object
-
#sum_of_squares(m = nil) ⇒ Object
Calcualte sum of squares.
-
#variance_sample(m = nil) ⇒ Object
Calculate sample variance.
Methods included from Statsample::VectorShorthands
#to_numeric, #to_scale, #to_vector
Instance Method Details
#mean ⇒ Object
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# File 'lib/statsample.rb', line 61 def mean self.sum / size end |
#prefix(s) ⇒ Object
:nodoc:
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# File 'lib/statsample/dataset.rb', line 13 def prefix(s) # :nodoc: self.collect{|c| s+c.to_s } end |
#sd ⇒ Object
Calculate sample standard deviation
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# File 'lib/statsample.rb', line 78 def sd m ||= mean Math::sqrt(variance_sample(m)) end |
#suffix(s) ⇒ Object
:nodoc:
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# File 'lib/statsample/dataset.rb', line 16 def suffix(s) # :nodoc: self.collect{|c| c.to_s+s } end |
#sum ⇒ Object
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# File 'lib/statsample.rb', line 57 def sum inject(:+) end |
#sum_of_squares(m = nil) ⇒ Object
Calcualte sum of squares
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# File 'lib/statsample.rb', line 66 def sum_of_squares(m=nil) m ||= mean self.inject(0) {|a,x| a + (x-m).square } end |
#variance_sample(m = nil) ⇒ Object
Calculate sample variance
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# File 'lib/statsample.rb', line 72 def variance_sample(m=nil) m ||= mean sum_of_squares(m).quo(size - 1) end |