#3886 plot2d implicit function

[Nicholas Strauss]

(%i1) plot2d (x^2-y^3+3*y=2, [x,-2.5,2.5], [y,-2.5,2.5])$
plot2d: expression evaluates to non-numeric value everywhere in plotting range.
plot2d: nothing to plot.

---

Maxima version: "5.37.2"
Maxima build date: "2015-10-30 02:08:33"
Host type: "x86_64-unknown-linux-gnu"
Lisp implementation type: "GNU Common Lisp (GCL)"
Lisp implementation version: "GCL 2.6.12"

---

The above information is also reported by the function 'build_info()'.

[Robert Dodier]

Hi Nicholas, in Maxima 5.37, implicit plots were handled by a separate function implicit_plot, not by plot2d. I think ? implicit_plot should show some info about it. You will need to say load(implicit_plot); before trying to call it.

There have been many bug fixes and other improvements since 5.37 -- can you update to a newer version of Maxima? The most recent version is 5.45.

[Nicholas Strauss]

Hi Robert,

Great thanks! implicit_plot works well.

I am running Maxima on Debian and this is the default release. Any idea
on how to get updates easily on Debian?

Nicholas

[Gunter Königsmann]

Using Debian basically means that you absolutely don't want to be surprised by updates, but want to profit from a quite active team that cherry-picks small Bugfixes for the packages you have installed.

The best way of getting a new version might be to compile it yourself or to try a package from https://code.launchpad.net/~peterpall/+archive/ubuntu/wxmaxima-nightlies

Kind regards,

Gunter.

[Leo Butler]

"Gunter Königsmann" peterpall@users.sourceforge.net writes:

Using Debian basically means that you absolutely don't want to be
surprised by updates, but want to profit from a quite active team that
cherry-picks small Bugfixes for the packages you have installed.

That may be true for Debian stable.
Debian testing has the latest release of maxima.

https://packages.debian.org/search?keywords=maxima
https://packages.debian.org/bookworm/maxima

Leo

[Robert Dodier]

One way to get an up to date version is to build it from source code. This is pretty straightforward on Linux systems. Download a tar.gz from the "Files" tab above this page, and then:

$ sudo apt-get install texinfo
$ sudo apt-get install sbcl
$ tar xvzf maxima-5.nnn.tar.gz
$ cd maxima-5.nnn
$ ./configure --enable-sbcl
$ make
$ sudo make install

About texinfo, it's for building the documentation, and it might not be installed already. About SBCL, it's a Lisp implementation, and I recommend it. Other Lisp implementations are workable, too,

Another approach is to install a wxmaxima package from the peterpall package repository mentioned by Gunter. I believe that installs command line maxima in addition to the wxmaxima GUI, although I'm not 100% sure.

[Robert Dodier]

For the record, I see that the example given in the original bug report, plot2d (x^2-y^3+3*y=2, [x,-2.5,2.5], [y,-2.5,2.5])$, works as expected with recent versions of Maxima, I think the plot2d(f(x, y) = c, ...) syntax was introduced in Maxima 5.45. Anyway I just tried it with current Git version (post-5.45) and it works as expected.

[Jaime E. Villate]

Of course it works, because that example was taken from the manual (https://maxima.sourceforge.io/docs/manual/maxima_64.html)