title: R - as.numeric matrix
body: <p>I am new to R and I am trying to convert a dataframe to a numeric matrix using the below code</p>
  
  <pre><code>expData &lt;- read.table("GSM469176.txt",header = F)
  expVec &lt;- as.numeric(as.matrix(exp_data))
  </code></pre>
  
  <p>When I use as.matrix, without as.numeric, it returns some numbers (as below)</p>
  
  <pre><code>0.083531    0.083496    0.083464    0.083435    0.083406    0.083377    0.083348"                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
  [9975] "-0.00285  -0.0028274  -0.0028046  -0.0027814  -0.0027574  -0.0027319  -0.0027042  
  </code></pre>
  
  <p>but when I put in the as.numeric, they are all converted to "NA"</p>
  
  <p>I apologize if someone has asked this question before but I can't find a post that solves my problem.
  Thanks in advance</p>