Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am trying to plot the following parametric equation in gnuplot:

fx(t) = -35*cos(t) + 65*cos(-.35*t)

fy(t) = -35*sin(t) - 65*sin(-.35*t)

I am not using much more code than pasted above. The result is fairly ugly.It is very angular, and obviously there must be some command to smooth it out.

I have tried to use commands like smooth cspline and smooth bezier to no avail.

How do I make a nice smooth graph of this function in gnuplot?

share|cite|improve this question
I cant answer your question; but the graph is quite pretty, as produced by JSXgraph. I'm tempted to post it. – David Mitra Jan 11 '13 at 15:57
up vote 1 down vote accepted

Just change the samples value typing, for example,

set samples 10000

Here is the complete command:

set parametric
set xrange [-110:110]
set yrange [-110:120]
set trange [0:300]
set samples 10000
plot -35*cos(t)+65*cos(-.35*t),-35*sin(t)-65*sin(-.35*t)

enter image description here

share|cite|improve this answer
Yes, that's it. I was using the samples with values of 30 or 60. I had no idea I had to go that high. I tried it with 20000, but there was no difference. It would be nice to know how to make the graph with the smoothest possible seems that after 10000 it is as smooth as it can get. – Paul Jan 12 '13 at 3:59

This link may help to answer your question

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.