title: How to convert a daily times series into an averaged weekly?
body: <p>I am wishing to (arithmetically) average daily data and thus convert my daily time series into a weekly one.</p>
  
  <p>Following this thread: <a href="https://stackoverflow.com/questions/11129562/how-does-one-compute-the-mean-of-weekly-data-by-column-using-r">How does one compute the mean of weekly data by column using R?</a> , I am using the <strong>xts</strong> library. </p>
  
  <pre><code># Averages daily time series into weekly time series
  # where my source is a zoo object
  source.w &lt;- apply.weekly(source, colMeans)
  </code></pre>
  
  <p>The problem I am having is that it averages the series taking tuesday through next monday data.</p>
  
  <p>I am searching for options to average my daily data from monday through friday.</p>
  
  <p>Any hints?</p>
  
  <p>Here is a bit more:</p>
  
  <pre><code>    # here is part of my data, from a "blé colza.txt" file
  
  
      24/07/2012  250.5   499
      23/07/2012  264.75  518.25
      20/07/2012  269.25  525.25
      19/07/2012  267 522.5
      18/07/2012  261.25  517
      17/07/2012  265.75  522.25
      16/07/2012  264.25  523.25
      13/07/2012  258.25  517
      12/07/2012  253.75  513
      11/07/2012  246.25  512.75
      10/07/2012  248 515
      09/07/2012  247 519.25
      06/07/2012  243.25  508.25
      05/07/2012  245 508.5
      04/07/2012  236 500.5
      03/07/2012  234 497.75
      02/07/2012  234.25  489.75
      29/06/2012  229 490.25
      28/06/2012  229.75  487.25
      27/06/2012  229.75  493
      26/06/2012  226.5   486
      25/06/2012  220 482.25
      22/06/2012  214.25  472.5
      21/06/2012  212 469.5
      20/06/2012  210.25  473.75
      19/06/2012  208 472.75
      18/06/2012  206.75  462.5
      15/06/2012  203 456.5
      14/06/2012  205.25  460.5
      13/06/2012  205.25  465.25
      12/06/2012  205.25  469
      11/06/2012  208 471.5
      08/06/2012  208 468.5
      07/06/2012  208 471.25
      06/06/2012  208 467
      05/06/2012  208 458.75
      04/06/2012  208 457.5
      01/06/2012  208 463.5
      31/05/2012  208 466.75
      30/05/2012  208 468
      29/05/2012  212.75  469.75
      28/05/2012  212.75  469.75
      25/05/2012  212.75  465.5
  
  
  
  # Loads external libraries
  library("zoo") # or require("zoo")
  library("xts") # or require("xts")
  
  # Loads data as a zoo object
  source &lt;- read.zoo("blé colza.txt", sep=",", dec=".", header=T, na.strings="NA",     format="%d/%m/%Y")
  
  # Averages daily time series into weekly time series
  # https://stackoverflow.com/questions/11129562/how-does-one-compute-the-mean-of-weekly-    data-by-column-using-r
  source.w &lt;- apply.weekly(source, colMeans) 
  </code></pre>