title: Gnuplot negative x range and logscale
body: <p>I am trying to plot some data with Gnuplot and would like to use a logscale on the x axis. This does not work, Gnuplot gives the error "x range must be greater than 0 for log scale". I saw examples that used a logscale with negative values on the y axis and tried to do it similar for the x axis, but it seems I can not get it to work. Initially I thought it would be the zero values, but even when I remove them, it does not work.</p>
  
  <p>This is a little example:</p>
  
  <pre><code>stats 'stat_data1'
  num1=STATS_records
  stats 'stat_data2'
  num2=STATS_records
  
  set terminal pdf
  set output "Cumulative_noise.pdf"
  set autoscale yfix
  set autoscale xfix
  set key bottom right
  set xlabel 'Noise in dB'
  set ylabel 'Percent'
  set xrange [0:110] reverse
  set logscale x
  
  set style increment user
  set style line 2  lc rgb '#FF0000' lt 1 pt 1 ps 1
  set style line 3  lc rgb '#008000' lt 2 pt 2 ps 2
  set style line 4  lc rgb '#0000FF' lt 3 pt 3 ps 3
  
  plot 0/0 notitle,\
  'stat_data1' u (-$3) : ((100.0/num1)) title 'Node 1' smooth cumulative,\
  'stat_data2' u (-$3) : ((100.0/num2)) title 'Node 2' smooth cumulative
  </code></pre>
  
  <p>And here some data. First file:</p>
  
  <pre><code>1437818411 -54 -95 85.2 0.0
  1437818425 -54 -95 78.0 0.0
  1437818440 -71 -95 38.7 0.0
  1437818456 -70 -95 51.7 0.0
  1437818471 -71 -95 42.0 0.0
  </code></pre>
  
  <p>Second file:</p>
  
  <pre><code>1437818545 -50 -95 43.7 100.0
  1437818561 -51 -95 52.0 100.0
  1437818576 -50 -94 79.4 0.10744142234781584
  1437818592 -51 -94 16.6 0.308927509416507
  1437818605 -49 -95 85.2 0.04368438558438699
  </code></pre>
  
  <p>I hope somebody has an idea as this would be very convenient. Thank you in advance!</p>