CODEWITHSUNDEEP
plotgnuplot
thyme
thyme

Reputation: 428

Iterative parametric plot with gnuplot

I want to use the iterative plot function plot for in gnuplot for a parametric plot.

set parametric
f(x) = x
plot for [i=1:2] t,f(i*t)

However, as I learned in this Question, the for iteration ends after a comma. So the iteration only applies to t and not to f(i*t). But since a parametric plot needs a pair of functions separated by a comma, how can I tell gnuplot to iteratively plot my parametric plot?

Upvotes: 3

Views: 180

Answers (1)

Joce
Joce

Reputation: 2332

Did you actually try it? gnuplot distinguishes a comma between parametric coordinates and the end of a plot-element as it is called (which can contain a for-loop): this is simply done by counting the number of coordinates given.

E.g.,

set parametric
set size ratio -1
plot for [i=1:3] cos(t),i*sin(t) title "Ellipse ".i, \
     for [i=1:3] i*cos(t),i*sin(t) title "Circle ".i

If you do

plot for [i=1:3] cos(t),i*sin(t),i*cos(t),i*sin(t)

then you keep the 3 ellipses (well, including the circle when i=1), and have one circle plotted for i=3 (the value i kept after the for loop) from the last pair of coordinates.

Upvotes: 2

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