plot

GNUPLOT

gnuplot demo   Kawano's Gnuplot Tutorial   gnuplot 3.5 User's Guide  

The order of arguments is important. eg notitle after using .

plot 'myfile.txt' using 1:2
-each line contains x y pair eg
0.0 0.0
0.5 0.25
1.0 1.0


set output 'myfile.ps'
replot
$ lpr myfile.ps
set terminal x11
set output
replot
q - to kill plot

Points can be displayed with
smooth csplines
with points
with lines
with lp


plot [0:] [0:] 'myfile.txt' using 1:2 smooth csplines notitle
-sets axes to include the origin

set nokey
set noxtics - turns of x-axis tics
set noytics
set noborder

plot "data.txt" using (log($1)):(log($2)) smooth csplines notitle - quadratic data gives straight line with gradient of 2.

Multiple plots
gnuplot> plot "results2.txt" using ($1):($2) notitle, "results2.txt" using ($1):($2) smooth csplines notitle
gnuplot> plot "results2.txt" using (log($1)):(log($2)) notitle, "results2.txt" using (log($1)):(log($2)) smooth csplines title "log log graph"


To run a script file interactively use the load command.
load 't6.txt'
The quotes are necessary.

Script file gnup01.txt
$ gnuplot gnup01.txt   where the script file is given below. As this is ment not to be used in interactive mode the output was set to the graphics file.

set term postscript
set output "output1.ps"
f(x) = exp(-x**2)
plot [0:0.3] f(x)

The file needs to be viewed with a postscript editor. An alternative is this hack to both print and view your results.

f(x) = exp(-x**2)
plot [0:0.3] f(x)
pause -1 
set term postscript
set output "output1.ps"
replot

gnuplot can be used as a calculator.
gnuplot> print pi
3.14159265358979
gnuplot> print 34%5
4