Module: Distribution::Weibull::Ruby_

Defined in:
lib/distribution/weibull/ruby.rb

Class Method Summary collapse

Class Method Details

.cdf(x, k, lam) ⇒ Object

Returns the integral of the Weibull distribution from [-Inf to x]



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# File 'lib/distribution/weibull/ruby.rb', line 12

def cdf(x, k, lam)
    return 0.0 if x < 0.0
			       return 1.0-Math.exp(-(x.to_f/lam.to_f)**k)
end

.p_value(y, k, lam) ⇒ Object

Returns the P-value of weibull



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# File 'lib/distribution/weibull/ruby.rb', line 19

def p_value(y, k, lam)
    return 1.0 if y > 1.0
			       return 0.0 if y < 0.0
    return -lam*(Math.log(1.0-y))**(1.0/k)
end

.pdf(x, k, lam) ⇒ Object 



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# File 'lib/distribution/weibull/ruby.rb', line 5

def pdf(x, k, lam)
    return 0.0 if x < 0.0
			       return ((k.to_f/lam.to_f)*(x.to_f/lam.to_f)**(k-1.0))*Math.exp(-(x.to_f/lam.to_f)**k)
end