18,517 reputation
13889
bio website sites.google.com/a/unca.edu/…
location Asheville, NC
age
visits member for 2 years, 6 months
seen 7 mins ago

I've been a professor of mathematics at The University of North Carolina - Asheville since 1997. I've been using Mathematica since I started graduate school in mathematics at Ohio State in 1989. At that time, we used version 1.1 (as I recall) to teach calculus in our Calculus and Mathematica classes. I've used it pretty much continuously in my teaching and research since then.

In addition to my posts on SE, you can find some of my papers, teaching notebooks and other Mathematica based oddities strewn throughout my website.

In recent years, I've also worked as a part-time consultant to Wolfram Research focusing on development of mathematical content for WolframAlpha.


Jan
7
comment Why doesn't Mathematica use uniform criteria for validating Options?
@belisarius Well, I know that Import takes options, it just doesn't have options. More precisely, it just passes down the line, in the same way that Show does. In that case, though, you do get complaint's when using non-Graphics options. But Import and Export pass their options down to lower level functions that probably act more quietly. I am with you, though. It would be nice to see the warning.
Jan
7
comment Why doesn't Mathematica use uniform criteria for validating Options?
Note that Options[Image] returns an empty list, thus, Image has no options.
Dec
31
comment What is the difference between Reduce and Solve?
@IstvánZachar I added simple examples for both points 1 and 2. Of course, Itai, is free to change or modify those, but I do think some example is helpful.
Dec
26
comment How do I identify each surface in a multi-surface Plot3D?
Probably easiest to generate each plot separately using a different ColorFunction for each; then use Show to combine the three images.
Dec
24
comment How to draw Fractal images of iteration functions on the Riemann sphere?
Would you care to share where your example spherical projection came from?
Dec
21
comment Creating an animation illustrating the time-evolution of a pre-computed orbit
@Vaggelis_Z As with most options, "AnimationRepetitions" is well documented: reference.wolfram.com/mathematica/ref/Animate.html#878404649
Dec
21
comment Creating an animation illustrating the time-evolution of a pre-computed orbit
Why not perform the numerical integration in Mathematica as well? NDSolve is amply able to deal with equations of motion.
Dec
16
comment How can I improve the speed of eigenvalue decompositions for large matrices?
@P.Fonseca I'm certainly planning on that! I don't anticipate significant improvement, though, given the areas of development in V9, but never hurts to check.
Dec
16
comment RegionPlot3D in cylindrical or spherical coordinates?
And, it should work in V8 or even earlier.
Dec
16
comment RegionPlot3D in cylindrical or spherical coordinates?
@rogerl Clearly, the situation could be better. It should be possible, at least, to draw mesh lines that are indicative to your chosen coordinate system. Would that be of interest?
Dec
16
comment RegionPlot3D in cylindrical or spherical coordinates?
Right. I think the answer is: "no, that capability is not explicitly supported", although I am not so certain of that that I wanted to put it in my answer - particularly, given V9's new capabilities. Thus, my answer addresses the simplest way I know of to go from a rho, phi, theta expression to a region plot.
Dec
16
comment How to draw a great circle on a sphere?
There are any number of demos on the Wolfram Demonstrations site that might help. You can search explicitly for "Great Circle": demonstrations.wolfram.com/search.html?query=great%20circle
Dec
15
comment Symbolic calculation
I gotta learn how to use Boole better!
Dec
14
comment How can Mathematica solve this set of differential equations?
Nice - and thanks for the contribution! I formatted your code by adding spaces at the beginnings of the lines and added a picture. If you examine the scale of the picture, you'll notice that the x range is essentially constant, at least with these initial inputs. You might try ParametricPlot3D to visualize the whole thing.
Dec
14
comment How can Mathematica solve this set of differential equations?
@TehHO Then I suggest you rephrase your question in terms of NDSolve, since we don't expect DSolve to work anyway.
Dec
14
comment How can Mathematica solve this set of differential equations?
It's a non-linear system. There's no reason to think that it can be solved in closed form, except in fairly special cases. You need to look into NDSolve. There are loads of NDSolve examples in the documentation and on this site. Here's one: mathematica.stackexchange.com/questions/13072/…
Dec
14
comment Possible bug in v9.0 Rest[] function
@rm-rf Thanks for the edit!
Dec
14
comment Possible bug in v9.0 Rest[] function
Works fine for me. Has anyone else been able to reproduce this? If not, I'd vote to close.
Dec
13
comment What bugs have you found in mathematica 9?
@LeonidShifrin Yes, you're right - I'm generally in favor of anything that makes Mathematica more open!
Dec
13
comment What bugs have you found in mathematica 9?
@acl I'm on board - Leo's comment on infrastructure convinced me!