## Generic Gnuplot

Some generic gnuplot stuff

**Gnuplot: **

Not so Frequently Asked Questions:

http://t16web.lanl.gov/Kawano/gnuplot/set-e.html

Gnuplot site: http://gnuplot.sourceforge.net/ (contains demos)

Generic gnuplot usage with gp file to plot points in x,y dimensions:

`gnuplot makeplot.gp > plot.eps`

makeplot.gp:

1 set terminal postscript eps enhanced

2 set key box

3 plot "out.txt" using 1:2 title 'data' with points

To make PDF plots:

`gnuplot makeplot.gp | epstopdf --filter > plot.pdf `

**Plotting n-th roots**

When plotting a function, with an exponent, like f(x)=x^2, you need to replace the “^” with “**”: `f(x)=x**2`

Now say you want the square root, you have two options:

`f(x)=sqrt(x)`

or, more generic:

`f(x)=x**(1/2)`

WRONG! this gives a straight line, because gnuplot sees the “1” as an integer and rounds 1/2 to the nearest integer.

`f(x)=x**(1.0/2)`

Does exactly what you need here. Of course it also works for cube roots, n-th roots and arbitrary stuff like:

`f(x)=1-(1-x)**(1.0/(n(x)-1))`

with n(x) also defined as some function of x.