I am trying to plot some data with en ellipse on top in gnuplot. I want to plot the ellipse parametrically, and not using set object ellipse.
The following code will plot the data:
plot "my_file.dat" u 1:2
The following code will plot the ellipse:
x0 = 1
y0 = 2
a = 3
b = 2
f(t) = x0 + a*cos(t)
g(t) = y0 + b*sin(t)
set parametric
plot [0:2*pi] f(t),g(t)
How do I combine these plots in a single plot?
I am running gnuplot 5.2.
Well, check the gnuplot manual or on the gnuplot console help plot.
Syntax:
plot {<ranges>} <plot-element> {, <plot-element>, <plot-element>}
Simply add a plot element separated by comma. For better readability you may want to put it into a new line using \ as last character of the previous line.
plot [0:2*pi] f(t),g(t), \
"my_file.dat" u 1:2
Any plot command in parametric mode can be reformulated to produce the same plot in non-parametric mode using the pseudofiles '+' for one parametric variable or '++' for two parametric variables.
So your
set parametric
plot [0:2*pi] f(t),g(t)
is exactly equivalent to
unset parametric
plot sample [t=0:2*pi] '+' using (f(t)) : (g(t))
In this form it is trivial to mix it with other data plots.
