title: .I want to do a pairwise.t.test of every column against every column in a dataframe
body: <p><a href="https://i.stack.imgur.com/ZM5xR.png" rel="nofollow noreferrer">violin plots generated from data frame</a>
  The numbers in each column represent localisation of signal relative to another signal inside nuclei of cells. There are 3 treatment conditions and 7 time points of treatment + 2 controls giving a total of 23 columns (see violin plots). 
  I would like to perform a t-test or a Wilcox t-test with each column to each column. I think I have done it before with a <code>pairwise.t.test(Chr)</code>. However, the function requires to define how you group your data and I would like to group mine by columns.
  I've imported my data:</p>
  
  <pre><code>Chr &lt;- read_csv("Chromocenters-intensity.csv", 
  +     na = "NA")
  </code></pre>
  
  <blockquote>
    <p>Parsed with column specification: cols(   .default = col_double() )</p>
  </blockquote>
  
  <p><a href="https://i.stack.imgur.com/qZ1GY.png" rel="nofollow noreferrer">Imported dataset into R</a></p>
  
  <p>And then tried:</p>
  
  <pre><code> pairwise.t.test(Chr, cols())
  </code></pre>
  
  <blockquote>
    <p>Error in order(y) : unimplemented type 'list' in 'orderVector1'</p>
  </blockquote>
  
  <pre><code>pairwise.wilcox.test(Chr,g=cols(Chr))
  </code></pre>
  
  <blockquote>
    <p>Error: Some <code>col_types</code> are not S3 collector objects: 1</p>
  </blockquote>
  
  <p>I do not understand what the errors mean. </p>
  
  <p>a normal t.test works fine:</p>
  
  <pre><code>t.test(Chr$S0,Chr$S1)
  </code></pre>
  
  <blockquote>
    <p>Welch Two Sample t-test</p>
    
    <p>data:  Chr$S0 and Chr$S1 t = 0.85955, df = 154.12, p-value = 0.3914
    alternative hypothesis: true difference in means is not equal to 0 95
    percent confidence interval:  -1.920629  4.879370 sample estimates:
    mean of x mean of y 
    100.41579  98.93642</p>
  </blockquote>
  
  <p>but how do I scale it up to include every column by every column?</p>
  
  <p>Thank you</p>