title: GNUPLOT: warning: Skipping data file with no valid points Can't plot with an empty x range
body: <p>I'm new to this. Currently, I am trying to plot my memory consumption for my server.
  I'm using Gnuplot and getting stuck at  </p>
  
  <p><strong>warning: Skipping data file with no valid points
           Can't plot with an empty x range!</strong></p>
  
  <pre><code>set title "Memory Growth" font ",20" textcolor lt 2
  set xdata time
  set timefmt "%m-%d-%y %H:%M:%S"
  set format x "%m-%d-%y\t%H:%M:%S"
  set xrange ["12/18/19":"12/24/19"]
  set format y '%.0s%cB'
  set xlabel "Time"
  set xtics rotate by -270 
  set xtics out offset 0,-1.0
  set ylabel "Memory (GB)"
  set datafile separator "\,"
  plot    'TRDFDSERVER19_System Monitor Log.csv' using 1:2 title '19\ProcessPrivate,Bytes' with line,\
          'TRDFDSERVER19_System Monitor Log.csv' using 1:3 title '19\ProcessVirtual Bytes' with line,\
          'TRDFDSERVER19_System Monitor Log.csv' using 1:4 title '19\ProcessPrivate Bytes' with line,\
          'TRDFDSERVER19_System Monitor Log.csv' using 1:5 title '19\ProcessVirtual Bytes' with line
  </code></pre>
  
  <p>Example input</p>
  
  <pre><code>12/18/2019 06:29:30.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:31.030,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:32.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:33.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:34.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:35.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:36.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:37.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:38.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:39.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:40.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:41.029,1699074048,2442911744,102342656,831528960
  12/18/2019 06:29:42.029,1699074048,2442911744,102342656,831528960
  </code></pre>
  
  <p><strong>Edit</strong>                                                                                                                         <strong>^
           all points y value undefined!</strong> </p>
  
  <p>After the problem above is fixed. Now, i got "Y value" undefine. Any suggestion. Thanks</p>