title: Running multiple, simple linear regressions from dataframe in R
body: <p>I have a dataset (data frame) with 5 columns all containing numeric values.  </p>
  
  <p>I'm looking to run a simple linear regression for each pair in the dataset.</p>
  
  <p>For example, If the columns were named <code>A, B, C, D, E</code>, I want to run <code>lm(A~B), lm(A~C), lm(A~D), ...., lm(D~E)</code>,... and, then I want to plot the data for each pair along with the regression line.  </p>
  
  <p>I'm pretty new to R so I'm sort of spinning my wheels on how to actually accomplish this.  Should I use <code>ddply</code>?  or <code>lapply</code>?  I'm not really sure how to tackle this. </p>