Class: Statistics::Distribution::Uniform

Inherits:
Object
  • Object
show all
Defined in:
lib/statistics/distribution/uniform.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(a, b) ⇒ Uniform

Returns a new instance of Uniform.



6
7
8
9
 
# File 'lib/statistics/distribution/uniform.rb', line 6

def initialize(a, b)
  self.left = a.to_r
  self.right = b.to_r
end

Instance Attribute Details

#left ⇒ Object

Returns the value of attribute left.



4
5
6
 
# File 'lib/statistics/distribution/uniform.rb', line 4

def left
  @left
end

#right ⇒ Object

Returns the value of attribute right.



4
5
6
 
# File 'lib/statistics/distribution/uniform.rb', line 4

def right
  @right
end

Instance Method Details

#cumulative_function(value) ⇒ Object 



19
20
21
22
23
24
25
26
27
 
# File 'lib/statistics/distribution/uniform.rb', line 19

def cumulative_function(value)
  if value < left
    0
  elsif value >= left && value <= right
    (value - left)/(right - left)
  else
    1
  end
end

#density_function(value) ⇒ Object 



11
12
13
14
15
16
17
 
# File 'lib/statistics/distribution/uniform.rb', line 11

def density_function(value)
  if value >= left && value <= right
    1/(right - left)
  else
    0
  end
end

#mean ⇒ Object Also known as: median 



29
30
31
 
# File 'lib/statistics/distribution/uniform.rb', line 29

def mean
  (1/2.0) * ( left + right )
end

#variance ⇒ Object 



35
36
37
 
# File 'lib/statistics/distribution/uniform.rb', line 35

def variance
  (1/12.0) * ( right - left ) ** 2
end