18,289 reputation
13888
bio website sites.google.com/a/unca.edu/…
location Asheville, NC
age
visits member for 2 years, 6 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.


Jun
20
comment Why is my rasterized graphic blank?
You should certainly indicate what version and OS you're working with for this type of question. The code works fine for me in version 9.0.0 on Mac OSX 10.7.4.
Jun
17
comment Handling Overflow
It would be nice to have more details about what you are doing. If you're iterating a polynomial, for example, there's a simple bound on the absolute value of the iterate, beyond which, you are guaranteed the orbit will diverge to Infinity. It's easy to incorporate this into a loop or a NestWhileList. One issue with Check is that the Overflow[] won't be detected until after it happens. That's way too late, if you're working with compiled code.
Jun
8
comment How to scrape the headlines from New York Times and Wall Street Journal?
@RodLm Yes, that is pretty awesome, isn't it. Mathematica's import/export is generally outstanding in two ways - the broad range of filetypes it works with and the way it consistently represents things in it's own language. You might also be interested in this question, which deals with importing HTML as XML.
Jun
5
comment Combining Graphics & ContourPlot using Show
@0x4A4D That was the first thing I thought of. On Mac OS, at least, the borders of the individual polygons show up as in this question, which is not so attractive.
Jun
4
comment Combining Graphics & ContourPlot using Show
You can see that the area is under the contour shading by setting ContourShading->None in the ContourPlot.
Jun
4
comment Large Number times Tiny Number
I'm curious, where do numbers like 1234567891234567889998.5 come from? I mean, is it a real application? Or is it specifically a test of precision?
Jun
2
comment Mathematica8 can compile this function but Mathematica 9 can't if I set CompilationTarget -> “C”
@OleksandrR. But Print, so far as I know, is not compilable. It certainly doesn't appear in the list Compile`CompilerFunctions[] and CompilePrint[cf1] reveals a callback to MainEvaluate.
Jun
2
comment Mathematica8 can compile this function but Mathematica 9 can't if I set CompilationTarget -> “C”
Although I haven't tried it, I'm certain that @halirutan is correct so, probably, V9 is doing a better job of flagging uncompilable functions In addition, I'd point out that I don't see any output coming from your function. Perhaps, you should replace Do with Table and remove the semi-colon from the final statement inside the loop.
May
31
comment Find limit of Interpolated function
Uhmm... NLimit?
May
31
comment Find limit of Interpolated function
Limit is a purely algebraic tool. You could try NLimit from the NumericalCalculus package. I concur with J.M., however, that your specific example would be best approached with f'.
May
26
comment Common tangent to a curve
@cosmicraga Yes, based on the picture.
May
26
comment Common tangent to a curve
@beli Just a guess.
May
26
comment Common tangent to a curve
So sorry! And with a bandaged thumb, too. :)
May
24
comment Having used Mathematica as a “gateway” language, where to from here?
@Ajasja Yes, definitely! I think you made some particularly valid points about Mathematica's gobbling of memory for large scale linear algebra problems. I personally, though, have some very strong, and sometimes conflicting, feelings surrounding the whole open source issue. On balance, I tend not to be swayed by that alone. That's a whole other can of worms that can't be discussed just here, though.
May
23
comment Having used Mathematica as a “gateway” language, where to from here?
@Stefan Well, there's no question that Perl's original design was quite domain specific and it's expanded name reflects that. (That's why I referred to its "originally intended domain".) Of course, it's grown since then and it's fair to ask how well it's done at expanding into other domains. I honestly don't know, as I've not used it a lot since the mid-90s. In this regard, I think your example is not too good.
May
23
comment Having used Mathematica as a “gateway” language, where to from here?
To be clear, I rather like Perl for some of the same reasons that I like Mathematica. Both of them allow you to specify a program using a very small number of symbols and figuring out the way to do so can be quite fun. I used Perl quite a bit back in the mid 90s when I was first trying to seriously interact with students over the web. At that time, CGI via Perl or C was the only way to go. However, both Perl and Mathematica are rather domain specific and I don't know that I'd use either too much outside of their originally intended domain.
May
23
comment Having used Mathematica as a “gateway” language, where to from here?
I guess your primality tests are based on the regular expression primality checker. Cute, but I'm not sure that's the right code to convince the uninitiated that perl is readable. :)
May
17
comment Solving an ODE in power series
@J.M. Yes, that's definitely correct. Holonomic functions, in fact, satisfy linear ODEs by definition, which is exactly why I asked for an example, rather than post an answer.
May
17
comment Solving an ODE in power series
@J.M. Not true! It's buried in the Holonomic context
May
17
comment Solving an ODE in power series
Yes, there's a way. Do you have an example problem?