title: Extracting value specific rows in R
body: <p>I have a tab-delimited file with several columns. I want only those rows whose pvalue &lt; .05.  </p>
  
  <pre><code>Probe    A_sig  A_Pval   B_sig  B_Pval   C_sig   C_Pval    D_sig   D_Pval
  ILMN_122 12.31   0.04    23.6    0.4     124.5    0.04     567.4    0.008
  ILMN_456 56.12   0       23.89   0.55    567.2    0.214    56.35    0.01 
  ILMN_198 981.2   0.06    31.56   0.02    12.56    0.4      789.4    0.045
  ILMN_980 876.0   0.001   124.7   0.01    167.3    0.12     245.7    0.35
  ILMN_542 123.9   0.16    219.8   0.04    567.3    0.03     987.6    0.34 
  ILMN_567 134.1   0       542.5   0.24    12.56    0.65     5.67     0.56 
  ILMN_452 213.4   0.98    12.6    0.12    17.89    0.03     467.8    0.003 
  ILMN_142 543.8   0.04    245.6   0.89    456.34   0.001    12.67    0.002 
  ILMN_765 187.4   0.05    34.6    0.001   67.8     0.06     78.34    0.02
  </code></pre>
  
  <p>I need an output as follows:</p>
  
  <pre><code>     Probe  A_sig   A_Pval  B_sig     B_Pval   C_sig  C_Pval
     ILMN_122 12.31   0.04    32.56     0.004    311.4  0.001
     ILMN_980 876.0   0.001   123.4     0.001    678.9  0.02
     ILMN_142 543.8   0.04    56.56     0.015    67.8   0.04
  </code></pre>