Hello, I need to find relative extrema of an expression with inequalities. e.g. extrema(xi^2-x1^2-x2^2-xp^2-y^2,{xi-x1-x2+xp^2<=y^2},y); extrema command is not able to compute with inequalities constraints. Could you help me please? Thank you. Vladimir

Here are some possible bugs or limitations that I have come across while working with Tensors in the new physics package. I have done best of my efforts looking into the documentation, but it is still possible that the bugs I am listing are not bugs at all but outcome of lack of my knowledge in using Maple. My intention of creating this blog is to not to criticize but to help the Physics package development team in making updates. I appreciate their efforts for developing a much needed package for areas like fluid mechanics, continuum mechanics, theory relativity etc. Platform I am using: Maple Ver 11.01 on Mac OS X 10.4.10

Here's a question I was asked very recently: "When creating a plot, is it possible to specify the points at which the input expression should be evaluated?" The answer is "yes" for 2-D plots, and this is done with the 'sample' option. Use the command plot(f(x), x=a..b, sample=[x1, x2, ..., xn]) to have f(x) evaluated at points x1, x2, ..., xn. Note this produces a plot that includes points with x-values x1, x2, ..., xn. To produce a plot that contains only these points, you need to add the adaptive=false option as well.

I am trying to animate a sphere/ so that it kinda looks like the globe rotating. This is what I have so far. Also if any body knows how to tilt a sphere so that it is on an angle. that would greatly help. with(plots):with(plottools): globe:=sphere([2.0, 1.5, 1.5], 1): display(globe,scaling=constrained,style=patch,axes=normal):

Here's a substitution that briefly surprised me. It makes sense once you understand what is going on.

subs(true = false, proc() local i; for i to 3 do true; end do end proc);
 
           proc()  end proc

A little under two years ago, I started working on a little project we have here at NCSU. I should perhaps devote another blog entry to discussing that lovely little project... Anyway, there's a lot of Maple code in this project (as it is based in Maple), and I've had to untangle and understand what multiple programmers have done over the years. Last year, I came across one piece of code that I thought was exploiting a bug in Maple: We would take a long string of commands and parse the entire string with a single parse() command. I could never get a Maple worksheet to reproduce those results obtained from piping the command into Maple from the command line. Weird, no?

Waterloo Region, where our head office is located, has been called "The Quilt Capital of Canada". So a couple of years ago, I'd created a worksheet to generate a traditional "Log Cabin" quilt. I've made some minor updates to the example and added a "Trip Around the World Quilt". Having made a few quilts by hand myself, I can definitely say that it's easier to create a Maple one!

I would like to set up library(s) of routines that can be accessed as part of MapleNet applications. MapleNet applications are prevented from doing file i/o unless you specifically "unprotect" your server. Is there a way to set up libraries on my web server to safely get around it? Or is there a way to include my library routines while I'm building my maplet application, without copying and pasting in the source?

Here are more 3D Strange Attractors, the formula I used is a PickOver which is described in my last post, every plot has 10000 iterations(it could be more), you will find that some plots has shape of a Galaxy which I found very interesting because it is a relatively simple formula!! What more things could be so simple!!?? Gravitation:

Gravitation(different angle): Tornadoe: Tornadoe(different angle and coloring): Galaxies: Galaxies(different angle): Constelation: Thats all for now... If you have a question, suggestion, or an idea for an algorithm, write to me. Scasbyte. (scasbyte@hotmail.com)

Maple 11 has included indicial notation capability to its new Physics package. This is a good start in performing tensorial calculations using Einsteinian summation convention. However, I wish that Maple further adds the following capabilities to make this package of practical use to folks involved in tensor analysis. This wish list is based upon my personal experience in using tensor analysis for continuum-mechanics and is in no way representative of the community involved in other fields like the theory of relativity. 1) Both covariant and contravariant indices are denoted in subscript. Including the convention of posting counter and covariant indices in super and subscripts, respectively, will help to improve the readability of the printed results.

Hi! I'm ScasByte welcome to my MaplePrime blog.

If you are interested in 3d Strange Attractors but you don't know how to create it here I can show you how, create Strange Attractor is actually very easy, if you are new to Maple then you might this very useful.
Here is a link to the first 3d Strange Attractor(the most simple of all) a PickOver.

Here is the code to generate a PickOver:

Earlier today, I was re-reading an old post when I was inspired. The post asked how one could use typesetting rules to make the call of a procedure typeset as a binary operation. The example used in the post was something along the lines of: myproc(a,b); becomes a <symbol> b; Inspired by a response to that post, I started looking at the help page for the define command and doing some testing in Maple. I was ready to make a reply to that post, when I stumbled upon a mind-boggling error. In the time it's taken me to track down that error (and run various errands), the original post has vanished from my view. Perhaps it still exists somewhere, but for the life of me, I cannot find it; therefore, I post to the next most appropriate place to describe and discuss this shortcoming: This blog.

Here's a tip for people new to Maple or to 2-D input: always use a space for implied multiplication. 2-D math input in Maple allows for implicit multiplication, which is writing a multiplication operation without an explicit multiplication operator. An example is x y. The space is not always required in cases where there is no ambiguity. However, it is highly recommended that you include it. An example that catches many new users (and some experienced ones as well) is s(t+u). This does not mean s times t+u, but the function s applied to t+u

"I've seen this element before..." Often we are faced with the problem of building up sets incrementally, by removing pieces one at a time from a larger whole. The bottlenecks in this case are usually: 1) adding a small set X to a large set S (copies S and X, making this ~O(|S|+|X|)) 2) removing elements of the large set S from the small set X (binary search: |X|*log(|S|)) A classic example of this is a breadth-first-search. We start at one vertex of a graph and in each iteration we add the set of new neighbors X to the set of vertices S that have already been found. We can make this more useful by making the program return the sets of new neighbors found in each iteration, that is, the sets of vertices that are distance 1, 2, 3, etc. from the initial vertex.

The error message "too many levels of recursion" is sometimes misleading. In the problem below, the error source was an undefined list variable. This hint may help to find programming errors.