title: the bits in R to express integer
body: <p>R use 32-bit integers, 4 bytes (4*8=32, 1 byte=8 bits),max integer is 2^31-1= 2147483647.</p>
  
  <pre><code>intToBits(125)
  [1] 01 00 01 01 01 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  </code></pre>
  
  <p>There are 64 bits ,not 32 bits,32 pairs of 00 or 01(32*2=64) ,why?
  in the manual ,a raw vector with entries 0 or 1,what is the meaning of entries 0 or 1? </p>
  
  <p>In my opinion, <code>intToBits(125)</code> will generate<br>
  <code>10111110 00000000 00000000 00000000</code>    # it is 32 bits<br>
  not<br>
  <code>01 00 01 01 01 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00</code>.  # it is 64 bits  </p>