Minitest有时会提前终止,并显示netither完成或错误消息

我有一个测试文件, ipca_test.rb :

require "test_helper"
require "matrix" # Does needing to include this here mean I'm doing something wrong?

class IpcaTest < Minitest::Test
  def test_that_it_has_a_version_number
    refute_nil ::Ipca::VERSION
  end

  def test_it_does_something_useful
    refute false
  end

  def test_on_a_random_matrix
    p = rand(3..10)
    n = rand(20..50)
    m = Matrix.build(n, p) {|_, _| rand(-10.0..10.0)}
    pca = Ipca::Pca.new(m)
    eigenvalue, r = pca.first_principal_component
    puts "eigenvalue: #{eigenvalue}, r: #{r}"
    assert eigenvalue.kind_of? Numeric
    assert_equal Vector, r.class
  end
end

我要测试的程序是 ipca.rb :

require "ipca/version"

module Ipca
  class Error < StandardError; end

  class Pca
    def initialize data
      @data = data.class == Matrix ? data : Matrix.rows(data)
    end

    # see https://en.wikipedia.org/wiki/Principal_component_analysis#Iterative_computation
    def first_principal_component(c = 100, tolerance = 0.001) # not sure whether defaults are apropos
      p = @data.column_vectors.count
      r = Vector.elements(Array.new(p) {|_| rand}).normalize
      eigenvalue = nil
      c.times do
        s = Vector.zero(p)
        @data.row_vectors.each do |x|
          s += x.dot(r)*x
        end
        eigenvalue = r.dot(s) # ?
        error = (eigenvalue*r-s).norm
        r = s.normalize
        exit if error < tolerance
      end
      return [eigenvalue, r]
    end
  end
end

( Git repo of entire tree )

josie@josie-Inspiron-580:/var/www/html/ruby/ipca$ruby-Itest test/ipca_test.rb运行选项:--seed 44059

#运行:

..josie@josie-Inspiron-580:/var/www/html/ruby/ipca$ruby-Itest test/ipca_test.rb运行选项:--seed 57681

#运行:

test/ipca_test.rb运行选项:--seed 57222

test/ipca_test.rb运行选项:--seed 7474

#运行:

..josie@josie-Inspiron-580:/var/www/html/ruby/ipca$ruby-Itest test/ipca_test.rb运行选项:--seed 1938

..josie@josie-Inspiron-580:/var/www/html/ruby/ipca$ruby-Itest test/ipca_test.rb运行选项:--seed 61325

#运行:

..特征值:2027.68758011128,r:向量[0.0328854230122999, -0.09533529249551115, 0.3033273986606458, 0.07951734565050736, 0.3575555246291426, 0.41614419068773545, 0.4928822662304588, 0.28785088479078025, 0.5144766379975693] .

以0.037173s、80.7047次运行/秒、107.6063次断言/秒的速度完成。

3次运行,4次断言,0次失败,0次错误,0次跳过 josie@josie-Inspiron-580:/var/www/html/ruby/ipca$