title: Finding aggregate correlation of multiple columns against one column in r
body: <p>I have a data frame with 11 columns out of which 9 are numeric. I am trying to find out the correlation of 8 columns together against the remaining column i.e., correlation of 8 variables with 1 variable which should generate one value of correlation instead of generating 9 different values in a matrix.</p>
  
  <p>is it possible? or do I need to calculate the average correlation after calculating individual correlation?e.g., I am trying to find the correlation of X,Y,Z to A. Using the mentioned methods I get a matrix which gives me indivual score of association for X,Y,Z with A where as I need one score which takes into account all three X,Y &amp; Z.</p>
  
  <p>A simulated df is presented below for illustration purposes</p>
  
  <pre><code>          x            y           z   a
  1   1.72480753  0.007053053  0.32435032  10
  2   0.97227885 -0.844118498 -0.75534119  20
  3  -0.53844294 -0.036178789  0.89396765  30
  4   1.34695331  0.870119744  0.99400826  40
  5   0.02336335  0.514481676  0.95894286  50
  6  -0.15239307  0.386061290  0.73541287  60
  7  -0.29878116  1.615012645 -0.04416341  70
  8  -1.10907706 -1.581093487 -0.93293702  80
  9   2.73021114 -0.130141775  1.85304372  90
  10  0.22417487  1.170900385 -0.68312974 100
  </code></pre>
  
  <p>I can do correlation of each row and variable with a but what I want is correlation of x,y,z combined with a</p>
  
  <pre><code>corr.test(df[,1:3],df[,4])
  </code></pre>
  
  <p>I will appreciate any help towards this problem.</p>
  
  <p>Regards,</p>