Does anyone know of good tools for plotting implicit functions ? Ideally, I'd like something that could plot functions of the form f(x,y) = 0, and even contours of the form f(x,y) = c.
(for those who aren't hip with web jargon, a bleg is a beg on a blog ;)
http://matplotlib.sourceforge.net
ReplyDeleteIf you eventually want 3D contours, then VTK should do the job.
If you are OK with commercial tools, Mathematica's ContourPlot does it
ReplyDeletehttp://www.yaroslavvb.com/research/qr/implicit-plots/implicit.html
http://reference.wolfram.com/mathematica/ref/ContourPlot3D.html
I'd go with surf
ReplyDeletehttp://surf.sourceforge.net
It lets you plot implicit curves and surfaces, and does a surprisingly good job of it. Main drawback: it only takes algebraic specifications (i.e. f needs to be a polynomial), and it doesn't have comfortable rotation and zooming.
Mouse grab-and-pull rotation and zooming has been added to the surfer extension GUI
http://surfer.imaginary2008.de
ah that's the problem. my function has logs in it. But some of the other options seem doable.
ReplyDeleteMaple does it with implicitplot()
ReplyDeleteNot sure how great it is though...
Grapher (comes with every mac) seems to work pretty well. I tried plotting log(xy) = 1.
ReplyDelete-sergei
What an opportunity to advertize our tool ;-) (for algebraic curves only)
ReplyDeletehttp://exacus.mpi-inf.mpg.de/cgi-bin/xalci.cgi
You can try it online with our browser
Can't you just take g(x,y) = f(x,y)-c ?
ReplyDeleteTry TexasInstruments T-98 thay are compact for travel and you can usually buy them used;via. pawn shops, consignment shops, etc....
ReplyDeleteWith a little wiggling, the common and freely available gnuplot can do this: http://t16web.lanl.gov/Kawano/gnuplot/implicit/solve-e.html
ReplyDeleteMATLAB has the command contour and isosurf.
ReplyDeleteAmusingly grapher the OS X utility also plots implicits via extracting isosurfaces (or curves / contour lines).
I second the recommendation of gnuplot
ReplyDelete(http://www.gnuplot.info; alas the .org seems to be owned by a domain squatter).
It has excellent support for parametric functions (x = x(t,u), y = y(t,u), z = z(t,u)), and reasonable support for both 2-D and 3-D contours.
I used the free software available here
ReplyDeletehttp://www.padowan.dk/graph/
It has a utility called "relation" in which you may define functions of the form f(x,y)= C. It is meant for windows but I installed it just fine on Ubuntu-9.04 using wine. Works great.
Abhinav