Sunday, October 20, 2013

GNUPLOT Cheatsheet

This blog post will eventually contain all you need to know to create blog posts so I will not need to search for information again, since I keep forgetting details about the process every time.

 Steps to create beautiful graphs:

 1. Define output file characteristics
  •  SET TERMINAL [options]  
    •  a) Display in terminal: WTX [ size 350,262 enhanced font 'Verdana,10' ] -
      • size refers to X and Y which default are (640, 480) 
      • font refers to the font type and font size 
    •  b) Display in a png file: PNG [ nocrop enhanced medium size 350,262]
    •  c) Display in an svg file: SVG [ size 350,262 fname 'Verdana' fsize 10 ] 
    •  d) Display in a ps file: POSTSCRIPT eps size 3.5,2.62 enhanced color font 'Helvetica,20' linewidth 2 
      • size is given in inch 
    • e) Create the image in a TEX file: EPSLATEX size 8.89cm,6.65cm color colortext
      • create the plot with gnuplot; save it in graph.tex
      • run $latex graph.tex
      • run $dvips -o graph.ps graph.dvi
  •  SET OUTPUT '<file_name>'
    • NOTE: When working with output files, we need to set the name of the file where the graph will be saved
2. Define graphs's characteristics
  •  SET LABELS NAME 
    •  Sets the name of the axes and the points that should be display on the axes. 
      • set xlabel '{/Helvetica-Oblique <label_x_name> }' 
      • set ylabel '{/Helvetica-Oblique  <label_y_name>}' 
      • set xtics (value1, value2, value3, ...)
      • NOTE: in for the EPSLATEX output set the xlabel and ylabel in latex notation: set xlabel '$x$'
  • SET BORDER linewidth <size>
  • SET STYLE LINE <line_id> LINECOLOR rgb '#0060ad' LINETYPE <size> LINEWIDTH <size>
  • SET TICS SCALE <size>
  • SET XTICS ROTATE
  • SET XRANGE [xmin : xmax]
  • SET AUTOSCALE -- Let gnuplot determine the scale
  • SET KEY-- allow legend to appear. Use "TITLE" in the using clause to customize the legend 
  • SET LABEL <label_value> AT  x_value,y_value -- Set's a label on the point (x_value, y_value)
    • NOTE: use UNSET label to return to the default values
3. Restore the default configuration of terminal
  • SET TERM POP --restores the terminal to the default value (usually X11 or WXT)
  • SET OUTPUT --restores the output to default (terminal)
4. Plot the data from file (USING)
  • PLOT 'path_to/file_name' USING 1:2 title 'Graph title'
  • USING : states what are the values for the X axis (column 1) and values for the Y axis (column 2)
  • If only one dimension is given (i.e.,values for y axis are known) then first number should be skipped (e.g., using :2). Values will be displayed as given and the Ox axis will contain the line number where y value is found.
  • pt <option1>--for point type
  • ps <option2> --for point size (ex: using 1:2 pt 7 ps10)
  • lc rgb 'color_name_or_code' --colors the line or the point with the color given
  • Conditional Plot: ($1==0 ? $2:1/0) <=> If (value in column 1 = 0) then plot value in column 2 Else do not plot anything.

*NOTE: good blogposts to read more about this: