title: Writing to excel files in ruby using roo gem
body: <p>I am parsing Excel and Excelx file using Roo gem. But I am not sure how to write in those files.  <code>set_value(row, column, text)</code> method is not working.</p>
  
  <p>Code</p>
  
  <pre><code>@oo = Excelx.new('tes.xlsx')
  @oo.default_sheet = @oo.sheets.first
  
  def return_column
    keywords = ["website", "url"]
    keywords.each do |keyword|
    1.upto(@oo.last_column) do |n|
    data = @oo.cell(1, n)
    return n if data.downcase=~/#{keyword}/i
  end
  end
  end
  
  def return_rows
    n = return_n
    2.upto(@oo.last_row) do |row|
    data = @oo.cell(row, n)
    stack &lt;&lt; data 
   end
  end
  
  def appender
    @oo.set_value(1,11, "hey")
  end
  
   appender
  </code></pre>
  
  <p>The Error Message I'm getting is </p>
  
  <pre><code> /.rvm/gems/ruby-1.8.7-p352/gems/roo-1.10.1/lib/roo/generic_spreadsheet.rb:441:in `method_missing': private method `set_value' called for #&lt;Excelx:0x101221f08&gt; (NoMethodError)
  from /Users/bhushan/.rvm/gems/ruby-1.8.7-p352/gems/roo-1.10.1/lib/roo/excelx.rb:168:in `method_missing'
  from parser.rb:32:in `appender'
  from parser.rb:35
  </code></pre>