20,336 reputation
24397
bio website sites.google.com/a/unca.edu/…
location Asheville, NC
age
visits member for 2 years, 8 months
seen 1 hour 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.


Jul
14
comment How to find valleys of data using new function in V10 PeakDetect
Apply it to $-f$?
Jul
10
comment How do I solve a PDE with a strange boundary condition?
Thanks - mystery man!
Jul
2
comment Problems with NIntegrate
@Chenminqi Or, perhaps \[Pi]^2, as it now appears in the code block.
Jul
1
comment Unexpected Plot3D behaviour
You can also do h[u_] = pol1^2 - pol2^2 /. x -> u in your definition of h, i.e. Set, rather than SetDelayed.
Jun
27
comment Finding maximum or minimum of implicit functions
@Algohi - I've edited your question. Please make sure that I've retained your intended meaning.
Jun
25
comment Simple derivative not working
Glad it helped! Markdown in comments is somewhat different than markdown in a post, I believe.
Jun
23
comment Problem With NDsolve trying to simulate n-body-gravity problem
You might be interested in this notebook, which contains code to deal with a fairly large number of objects specified in {mass,pos,vel} form. When two objects collide, however, a singularity arises and you simply cannot expect to integrate past that point. You can use InterpolatingFunctionDomain to deal with it gracefully but that's about it.
Jun
16
comment Solution given by Wolfram Alpha but not _Mathematica_
The WolframAlpha result can be produced with Reduce[Log[x] == Log[j, Log[j, x]], j, Reals]. In general, you should not assume that Mathematica commands typed into WolframAlpha will be executed verbatim on the server side.
Jun
3
comment plotting a trig functions along with its envelope
I edited your question. You should make sure that I preserved your intended meaning.
Jun
3
comment plotting a trig functions along with its envelope
In that case, your sheath is given pretty much perfectly by $\pm 2\cos(t/2)$, but maybe that's not what you want?
Jun
3
comment plotting a trig functions along with its envelope
Well, you've got to give us some kind of input to start with.
Jun
3
comment plotting a trig functions along with its envelope
I'm guessing that's something like Cos[42x]+Cos[43x]?
May
21
comment 2D Visualization of links and knots
@RahulNarain I won't be using it anytime soon so feel free!
May
21
comment Extract a list of all built-in functions used in a notebook
You might also anticipate getting List, Set, and Times, since a=1 for example is equivalent to Set[a,1].
May
21
comment 2D Visualization of links and knots
@RahulNarain We can find all the crossings as follows: N[{ToRules[Reduce[{trefoil2d[t1] == trefoil2d[t2], 0 < t1 < 2 Pi, 0 < t2 < 2 Pi, t1 < t2}, {t1, t2}]]}].
May
20
comment 2D Visualization of links and knots
I must agree with Pickett. It would be much easier to provide a useful answer if we knew your input.
May
20
comment 2D Visualization of links and knots
@RahulNarain Better?
May
11
comment How to define a matrix with all elements 0?
Expanding on Oska's comment, if you simply define m[i_,j_]=0, then you'll get the array you want, since Array produces an array with elements m[i,j]. Oska did essentially this using a pure function.
May
10
comment How to plot this function?
@GabrielR. _?NumericQ is useful to prevent evaluation prior to an actual number being plugged in and I use it out of habit when defining functions using numerical procedures. Strictly speaking, it's not necessary here. If you were to try to plot $f'$, however, some errors would be issued. The With construct is simply a scoping mechanism to declare n as local. Module could have been used just as well.
May
9
comment How to find the period of an arbitrary mathematical function?
@RichardFateman There is an FAQ. Among other things, you'll learn that you can create new tags after you have 300 rep and how to format your posts.