What is the largest linear system that Maple can solve? You might be surprised to find out. In this article we present strategies for solving sparse linear systems over the rationals. An example implementation is provided, but first we present a bit of background. Sparse linear systems arise naturally from problems in mathematics, science, and engineering. Typically many quantities are related, but because of an underlying structure only a small subset of the elements appear in most equations. Consider networks, finite element models, structural analysis problems, and linear programming problems.
Sometimes it can be very useful to know the indices of entries (of an Array) which obey some conditions. The following procedure (which works for any Array) makes this possible:
`index/makeIndex` := proc(indices::list,array::Array,value::list)
# Retrieving from the Array
if nargs = 2 then return array[op(indices)]: end if:
# Storing in the Array
if nargs = 3 then array[op(indices)] := indices = op(value): end if:
end proc:
An example: For Array A find the set S of indices of entries being positive integers, using as an intermediate step the Array B with entries of the form "indices = value":
I am just getting started with Maple TA for Calc III. I am trying to solve LaGrange multipliers. When the solve command returns multiple sets of answers, how do I extract the specific values for the subs command?
$f=xyz;
$q=x^2+2y^2+3z^2-6;
$g=maple("f+mu*$q");
$exp1=maple("diff($g,x)");
$exp2=maple("diff($g,y)");
$exp3=maple("solve({$q,$exp1,$exp2},[x,y,mu])");
$ans1=maple("subs({x = ????,),y =???? )},$f)");
$ans2=maple("subs({x = ????,y = ????},$f)");
The question marks are where I am lost.
Hello,
I have been using MAPLE 10 for a long time, now I switched to MAPLE 11. With both versions I have been using the standard worksheet. The programs which I wrote for MAPLE 10 work for MAPLE 11 also. However, in MAPLE 11 the graphs that are produced by the programs seem to have a worse resolution. What could be the reason for that?
More precisely, I solve an ODE numerically and then plot the solution with the odeplot-command. Then, I save the graph as an eps-file (by right-clicking on it, selecting export and choosing eps). Using MAPLE 10 the eps-graph has an excellent reolution, not so when I use MAPLE 11.
I'm finally going to start my MaplePrimes blog, and I will post answers to some of the questions I get about the areas with which I'm familiar. Most of time, I get asked about 2-D plotting. Some of the information here may be repeated from forum comments, but hopefully, this will make it easier to find.
Unfortunately, my participation on MaplePrimes comes in spurts, as I try to find time between my other tasks, such as developing features for new releases. I tend to rely on the many Maple experts on MaplePrimes who very competently answer most questions that arise. I will, however, try to be diligent about adding a new tip at least once a week. Let's see if I can live up to my promise and get beyond this first post!
http://pari.math.u-bordeaux.fr/
PARI/GP is a widely used computer algebra system designed for fast computations in number theory (factorizations, algebraic number theory, elliptic curves...), but also contains a large number of other useful functions to compute with mathematical entities such as matrices, polynomials, power series, algebraic numbers etc., and a lot of transcendental functions. PARI is also available as a C library to allow for faster computations.
Originally developed by Henri Cohen and his co-workers (Université Bordeaux I, France), PARI is now under the GPL and maintained by Karim Belabas with the help of many volunteer contributors.
The following lines execute properly in Maple 10 and not Maple 11.
restart;
with(DEtools):
DEplot( diff(y(x),x)=8*x^3*y(x), y(x), x=-5..5, [[ y(0) = 4 ]], y=-5..5 );
When run in Maple 11, Maple seems to be doing a lot of extra dsolve/numeric calculations and then just hangs when dsolve/numeric/SC/IVPrun calls external hardware nonstiff integrator with evalhf = true.
In this episode Tom Lee takes some time to chat with three students working at Maplesoft for the summer. Laura Bradbury and Elyot Grant are both students at the University of Waterloo, respectively studying Computational Mathematics and Computer Science/Mathematics. Zach Daly is a Mathematics major at the University of Guelph. They discuss their opinions and experiences of using Maple in the student paradigm, and offer ideas for other students just starting out with Maple. Eithne Murray joins Tom to discuss Maple’s offerings and resources for students, and as always the latest news is covered, including information on the release of Vista-compatible Maple.
I am trying to get used to Maple 11 after a happy coexistence with Maple 10 Classic Worksheet. I have programs that take a long time to execute and I've gotten into the habit of using printf to write to the screen each time a counter is increased, for instance. In Maple 11, none of this information gets written until the program finishes execution (sometimes after hours) so my attempts to monitor progress are useless. What's going on and what's the correction? It would seem Maple is buffering unwantedly. ................Edgar
I am running Maple 11 with a mac-intel MacBook (13'' screen). I have been running a procedure for plotting a system of differentail equations that depend on an arbitrary parameter. The procedure works well for some "simple" parameters. For some more complicated parameters, the memory count (bottom right hand size) goes from near zero to over 500 M in six seconds ! A message appears: "kernel connection lost", and warns that such problems could be due to firewall settings, but all my firewall software is off.
This procesure on these parameters works just fine with Maple 10 running in a PowerBook G4 (firewall connection also off).
Hi,
I am fitting experimental data DATA(t) to a MODEL(t) with LSSolve. What would be the shortest way to plot the
residuals(t)?
Thanks,
Evgeni
Why is it that there is an XML attribute that I can add to a text field to make the text contained within read-only, but there does not seem to be an option in any menu to let me select certain text and make it read-only?
In older versions of Maple, I believe this option was available.
Type the following line into Maple as 2D-Input:
foo := "1 + 1";
And then type this next line into Maple as Maple Input:
bar := "1 + 1";
Yes, it's the same thing in two different variables, but try to parse them.
parse(foo); will work, whereas parse(bar); will return an error.
It seems that when the same string is entered in the "classic" Maple Input, something doesn't get tripped to convert the MathML markup into syntax that the parse() command will read.
Recently I have experienced two ways to loose a whole Maple document (if I had not had a slightly outdated backup copy):
1. Do NOT collaps and expand sections, because it may cause the document to explode in size, but much worse, make it virtually impossible to execute. It seems appaling to me that typographical considerations should destroy a perfectly sound document.
2. Do NOT write something like SubMatrix(Matrix,1..0,1..0), because the 0's makes the line unaccessible, but much worse, it makes it impossible to reload the whole document.
I'm using Maple 9.5. Has these fatal errors been corrected in Maple 11?
