<p>I'm in the need of a program for my laptop that will do 3D graphing of multivariable functions along with information displays of critical points, etc. Looking for something with a user-friendly interface (not a command-line program like gnuplot). Is there anything free or low-cost out there that's decent?</p>
<p>At the risk of sounding a little snarky, try this - <a href=“LMGTFY - Let Me Google That For You”>LMGTFY - Let Me Google That For You;
<p>The only one I can think of is perhaps TecPlot, but even though it has a GUI, it is still not user friendly. The bottom line is that in most cases, the more capable the software, the steeper the learning curve. You really are best off learning gnuplot or Matlab.</p>
<p>For Mac users, there is a graphing program provided by the OS that is very simple (I am not sure if it can display special data like critical points). For others, while MATLAB is not free, GNU Octave is, and Octave is equivalent to MATLAB for all basic uses. As long as you have fewer than a million or so values to enter, or a function, it is possible to make quite beautiful 3D graphs in LaTeX using pgfplots. Mathematica makes it easy to make okay-looking 3D graphs.</p>
<p>Okay, I see the writing on the wall. I’m supposed to take a Matlab class next spring, but I can start getting to know it now.</p>
<p>@vanimelde One thing about Octave. I installed both it and FreeMat on my Windows laptop. I always hear Octave mentioned first among Matlab alternatives, and am inclined to want to go with it. My only reservation is that FreeMat has a nice multi-pane command window very similar to Matlab’s, whereas Octave (at least the couple of compiled versions I’ve tried) runs in a pretty plain DOS command-line window. If there’s an alternative interface for Octave, I haven’t found it yet.</p>
<p>You can use any text editor (e.g., emacs, vim, notepad++, gedit, etc.) and compose your .m files, you don’t need to use a command-line interface.</p>
<p>The basics of MATLAB are quite easy, and it is almost certainly something you are going to need as an engineering student and professional. Might as well get the head start - your school likely offers it cheap or even free.</p>