Comments for Wellons's Weblog http://wellons.wordpress.com A Little Applied Mathematics Mon, 08 Jun 2009 10:56:32 +0000 http://wordpress.com/ hourly 1 Comment on Building a Picnic Table by wellons http://wellons.wordpress.com/2009/06/07/building-a-picnic-table/#comment-41 wellons Mon, 08 Jun 2009 10:56:32 +0000 http://wellons.wordpress.com/?p=149#comment-41 I use Sage, which doesn't do exactly what I want it to. I have to manually do some of the simplification of Eqn. (3) because otherwise it gets inexplicably hung up on things like "sqrt(x^2)". I bring the denominators up by multiplying by them, then I move both terms to the same side of the equation. Here's a sequence of commands that does the computer algebra simplification and solving in this blog entry: sage: expand((2 * x)^2 * (1 - (11 / (2 * x))^2) - (71 /2 - x)^2 * (11 / (29))^2 ) 3243*x^2/841 + 8591*x/841 - 1017005/3364 sage: solve([ 3243*x^2/841 + 8591*x/841 - 1017005/3364 ], x) [x == (-1276*sqrt(2071) - 8591)/6486, x == (1276*sqrt(2071) - 8591)/6486] As you can see, Sage has a command line interface. The text following "sage: " is text I typed. The other lines are results. Best of all, sage is free and seems to be a pretty active project. It looks like it has a windows version here: http://www.sagemath.org/download.html . There are more powerful computer algebra systems that cost money and are often purchased by labs and universities for their researchers. I would say to ask around. I use Sage, which doesn’t do exactly what I want it to. I have to manually do some of the simplification of Eqn. (3) because otherwise it gets inexplicably hung up on things like “sqrt(x^2)”. I bring the denominators up by multiplying by them, then I move both terms to the same side of the equation. Here’s a sequence of commands that does the computer algebra simplification and solving in this blog entry:

sage: expand((2 * x)^2 * (1 – (11 / (2 * x))^2) – (71 /2 – x)^2 * (11 / (29))^2 )
3243*x^2/841 + 8591*x/841 – 1017005/3364
sage: solve([ 3243*x^2/841 + 8591*x/841 - 1017005/3364 ], x)
[x == (-1276*sqrt(2071) - 8591)/6486, x == (1276*sqrt(2071) - 8591)/6486]

As you can see, Sage has a command line interface. The text following “sage: ” is text I typed. The other lines are results. Best of all, sage is free and seems to be a pretty active project. It looks like it has a windows version here: http://www.sagemath.org/download.html .

There are more powerful computer algebra systems that cost money and are often purchased by labs and universities for their researchers. I would say to ask around.

]]> Comment on Building a Picnic Table by Matt http://wellons.wordpress.com/2009/06/07/building-a-picnic-table/#comment-40 Matt Sun, 07 Jun 2009 13:04:50 +0000 http://wellons.wordpress.com/?p=149#comment-40 Thanks for the solution Jonathan! How does the computer algebra program work, does it have a friendly interface and could I run it on my PC? Also we got your post card last week, I guess as long as we can visit Jeff and Hurk there is no need to go to Paris. Thanks for the solution Jonathan! How does the computer algebra program work, does it have a friendly interface and could I run it on my PC?

Also we got your post card last week, I guess as long as we can visit Jeff and Hurk there is no need to go to Paris.

]]> Comment on AFCEA Fellowship Award Ceremony by Daniel Grossberg http://wellons.wordpress.com/2009/04/06/afcea-fellowship-award-ceremony/#comment-38 Daniel Grossberg Wed, 15 Apr 2009 03:32:05 +0000 http://wellons.wordpress.com/?p=141#comment-38 P.S. When you email me back, I have some funny crap to tell you about the GRE. P.S. When you email me back, I have some funny crap to tell you about the GRE.

]]> Comment on AFCEA Fellowship Award Ceremony by Daniel Grossberg http://wellons.wordpress.com/2009/04/06/afcea-fellowship-award-ceremony/#comment-37 Daniel Grossberg Wed, 15 Apr 2009 03:31:41 +0000 http://wellons.wordpress.com/?p=141#comment-37 Did I read this shit correctly that you are getting a PhD in 4 years?! How is that even possible?! Did I read this shit correctly that you are getting a PhD in 4 years?! How is that even possible?!

]]> Comment on AFCEA Fellowship Award Ceremony by Daniel Grossberg http://wellons.wordpress.com/2009/04/06/afcea-fellowship-award-ceremony/#comment-36 Daniel Grossberg Wed, 15 Apr 2009 03:30:33 +0000 http://wellons.wordpress.com/?p=141#comment-36 Congratulations! Congratulations!

]]> Comment on The Biggest Box Fedex Will Take by Daniel Grossberg http://wellons.wordpress.com/2009/03/10/the-biggest-volume-box-usps-will-handle/#comment-35 Daniel Grossberg Wed, 15 Apr 2009 03:29:05 +0000 http://wellons.wordpress.com/?p=115#comment-35 You should submit this one to Dr. Math (the leading blog for such things). I think he'd like it. You should submit this one to Dr. Math (the leading blog for such things). I think he’d like it.

]]> Comment on Why Web Comics are Better by The Gigcast » Blog Archive » Webcomic Wire - 3/23/09 http://wellons.wordpress.com/2009/03/10/why-web-comics-are-better/#comment-32 The Gigcast » Blog Archive » Webcomic Wire - 3/23/09 Mon, 23 Mar 2009 22:55:46 +0000 http://wellons.wordpress.com/?p=112#comment-32 [...] Weblog has an post entitled ‘Why Web Comics are [...] [...] Weblog has an post entitled ‘Why Web Comics are [...]

]]> Comment on First Steps on Your Business’ Online Presence by ideas4life http://wellons.wordpress.com/2009/03/03/first-steps-on-your-business-online-presence/#comment-29 ideas4life Sun, 08 Mar 2009 18:59:56 +0000 http://wellons.wordpress.com/?p=108#comment-29 Thanks for the information, waitig for future posts. Thanks for the information, waitig for future posts.

]]> Comment on Who I am by Daniel Grossberg http://wellons.wordpress.com/about/#comment-27 Daniel Grossberg Mon, 02 Mar 2009 06:42:09 +0000 #comment-27 Give me an example. Also, help me find my old (retired) Blogger account (it predates gmail, which is now a requirement for a Blogger). Give me an example.

Also, help me find my old (retired) Blogger account (it predates gmail, which is now a requirement for a Blogger).

]]> Comment on Who I am by wellons http://wellons.wordpress.com/about/#comment-26 wellons Wed, 18 Feb 2009 20:18:31 +0000 #comment-26 Haha, no. Big problems have big opportunities, and because they are math problems, they often have subtle and elegant solutions. That's what I love to look for. Haha, no. Big problems have big opportunities, and because they are math problems, they often have subtle and elegant solutions. That’s what I love to look for.

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