I have few basic questions on R Stem and Leaf Plot This data when I plot - 60 85 72 59 37 75 93 7 98 63 41 90 5 17 97

stem(data)

 0 | 577
 2 | 7
 4 | 19
 6 | 0325
 8 | 50378


Now If I reconstruct data it is 5, 7, 7, 27, 60, 63, 62, 65, 85, 80, 83, 87, 88

This does not produce the input in reverse.
With the default scale, you see that numbers left of the bar go up by two - hence anything after the 4 is forty-something or fifty-something:

&gt; stem(d,scale=1)

  The decimal point is 1 digit(s) to the right of the |

  0 | 577
  2 | 7
  4 | 19
  6 | 0325
  8 | 50378


Using scale=2, you'll see numbers left of the bar go up by one, so now you can get exact reconstruction of your input, since you input integers:

&gt; stem(d,scale=2)

  The decimal point is 1 digit(s) to the right of the |

  0 | 57
  1 | 7
  2 | 
  3 | 7
  4 | 1
  5 | 9
  6 | 03
  7 | 25
  8 | 5
  9 | 0378


Going further you can even split it by first and second five within each decade:

&gt; stem(d,scale=4)

  The decimal point is 1 digit(s) to the right of the |

  0 | 57
  1 | 
  1 | 7
  2 | 
  2 | 
  3 | 
  3 | 7
  4 | 1
  4 | 
  5 | 
  5 | 9
  6 | 03
  6 | 
  7 | 2
  7 | 5
  8 | 
  8 | 5
  9 | 03
  9 | 78


Stem plots do not always guarantee you can reproduce the data by reversing the process, and that's not what they're for.