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POAm I extending this inbuilt ruby class correctly?
 

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  1. POAm I extending this inbuilt ruby class correctly?
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    <p>In my rails app in lib/matrix.rb I have entered the following code to extend the inbuilt Matrix class:</p> <pre><code>module Matrix require 'matrix' class Matrix def symmetric? return false if not square? (0 ... row_size).each do |i| (0 .. i).each do |j| return false if self[i,j] != self[j,i] end end true end def cholesky_factor raise ArgumentError, "must provide symmetric matrix" unless symmetric? l = Array.new(row_size) {Array.new(row_size, 0)} (0 ... row_size).each do |k| (0 ... row_size).each do |i| if i == k sum = (0 .. k-1).inject(0.0) {|sum, j| sum + l[k][j] ** 2} val = Math.sqrt(self[k,k] - sum) l[k][k] = val elsif i &gt; k sum = (0 .. k-1).inject(0.0) {|sum, j| sum + l[i][j] * l[k][j]} val = (self[k,i] - sum) / l[k][k] l[i][k] = val end end end Matrix[*l] end end end </code></pre> <p>Is this the correct way to add methods to an existing class within the rails app? Should I have the <strong>require matrix</strong> line there?</p> <p>EDIT 1: Additional info provided</p> <p>I have now removed the require 'matrix' line.</p> <p>If I type the following test code in a view page, <strong>it only works if I delete my lib/matrix.rb file</strong>:</p> <pre><code>&lt;% require 'matrix' %&gt; &lt;% m = Matrix[ [0,0], [1,1] ] %&gt; &lt;%= m.column(0) %&gt; </code></pre> <p>Otherwise it gives the error:</p> <pre><code>undefined method `[]' for Matrix:Module </code></pre> <p>It appears that I am eliminating the default methods of the built in Matrix class when I try to extend the class. Is there a way around this error? </p>
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