I am using OpenMaple (kv->rtableCreate or RTableCreate) to allocate large rtables which I then fill with data before returning to Maple. It seems to be slow. For example, a table with 120 Mwords takes 1 second to allocate and 0.640 seconds to fill. I suspect this is because the table is initialized to zero. I would like to skip this initialization and maybe use malloc to allocate the table, however I want it to behave like a normal Maple object (ie: garbage collected if not referenced, etc). The documentation says it is important to set rts->foreign to true, but it doesn't say why. Will this prevent garbage collection ? I would also like to know the purpose of rts->foreign.

I read the help material for the roots command, but apparently don't understand it correctly. I've tried roots(x^2+x+1,I) and roots(x^2+x+1, complex) and the only thing returned is [ ]. How do I use the roots command to get complex roots? Thanks.

When I enter solve(x^4-x^3+1) I get 4 RootOf place holder solutions. For example RootOf(_Z^4-_Z^3+1, index = 1). This is very frustrating because I'm trying to obtain answers not place holders, and I cannot figure out how to make Maple solve the problem. Is Maple perhaps trying to tell me that it cannot solve the problem? If not, how do I force Maple to return answers instead of place holders, on this and similiar problems? Just as there is the quadratic equation for obtaining solutions to second degree equations, I understand that there are standard equations for solving cubics and quartics so I would be surprized if maple cannot solve x^4-x^3+1 symbolicly.

Working in usual programming languages there is a largest machine epsilon
with 1 + epsilon != 1.

Now I am working with floats in Maple and want something similar: given a
real constant x (as positive floating point number) and m:=floor(log10(x))
(= ilog10(x) scales the x (down or up) to be of size 1). 

My question is:

Does the following always evaluate to "true"

  x + epsilon = x; evalf(eval(%, epsilon= 1/10^(Digits-m)));

and to "false" if taking m+1 instead?


Sorry, stupidly can not find the answer in the docu ...

This is an error message when using printlevel with the RKF45 solver Many thanks

Hi, i'm a french student, i hope a little help. (sorry for my english) How can i make a 3d graph of an array with 2 variables ? I have try plot3d: plot3d(array[x,y], x=1..10, y=1..10); and then: Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct. In the help, it is said that plot works only with functions. Maybe i have to built a function with the array... I don't know in fact! Thanks for your help

>alias(phi=phi(x)): > U := u[0](x)*phi^(j-2): > cc := expand(6*U*(diff(U, x))): > select(has, cc, 1/phi^5); # can obtain > coeff(cc,phi^(2*j-5)); # obtain 0 0 > select(has, cc, phi^(2*j-5)); # obtian 0 0 I want to obtain the coefficents of variable,phi^(2*j-5), but both "coeff" and "selcet" are invaild. How to obtain the coefficents?? Many thanks in advance!

Hi.... I am facing some problem in solving a Non-linear differential equation using Maple 11. So many times maple 11 doesnot execute the command and comes out. Sometimes, it just says evaluating for a long time and nothing happens. I would be very happy if you can give me the solution of the same with an example. Regards Sripad

With my calculator, I can store and then use intermediate results in the following way. Lets say the result of an equation is 1.234 and I will be using those results in other calculations. If I enter 1.234->a where the arrow represents the store key, the value of 1.234 in now stored as "a" and I can use "a" in further calculations, for example 2a followed by enter will return 2.468. How do I do the same type of thing with maple? (Thank you)

With my graphing calculator (TI-voyage200) I can expand and collect multiple angles per the familiar trig foumulas. For example with my calculator I can enter tExpand(sin(2*x)) and 2*sin(x)*cos(x) is returned. To do the reverse I simply enter tCollect(2*sin(x)*cos(x)) and sin(2*x) is returned by my calculator. With Maple, I find that I can use expand(sin(2*x)) to get 2*sin(x)*cos(x) but collect(2*sin(x)*cos(x)) doesn't perform the reverse the operaton. How can I do the reverse operation, for instance by entering what command along with 2*sin(x)*cos(x) and have sin(2*x) returned???

Hello everyone,I'd like to ask a question. Using the "LinearAlgebra" package, is there a (automatic) way to create a matrix from the section of rows and columns of another matrix already in use? That is, we have A:= a 5X4 matrix and we want to create, let's say a 3X2 matrix from the elements of A that belong in the section of rows 2,4 and 5 and columns 2 and 4 of A. Ok, we can write a small routine, but I would like to know if there's a fast and straight way to do that. Thanks in advance!

Maple Professionals: This is my first time programming. I wish to compute a marginal analysis algorithm, where I basically want to find the best bang per buck in each step. I increase the variable s[i] one after another by 1 and look at the change in the perforance realtive to the cost. Then I wish to increase that s[i] by 1 for which I could see the largest increase in performance relative to cost. In the end I wish to stop when the performance measure DFR is larger than 85%. However at the moment I especially face the difficulty to raise that s[i] by one, which reached the largest relative performance increase. At the moment I got this far and would be more than grateful for any help from your side:

Does anybody have any other ideas for getting Maple TA content (questions/banks/modules)? The application center doesn't currently meet our schools needs, and the contacts I've met at conferences are very hesitant to share their content. I can appreciate that because I've spent countless hours this school year writing over 300 questions, and I too would be hesitant to simply give them away. I feel I've become pretty good at writing all different types of questions. I am a former computer programmer and that background has definitely helped me write difficult algorithms and complex components of maple-graded questions. However, the question-writing task has become very tedious and time consuming for my school's needs. Our school is a tablet school which means we are doing away with the standard book/pencil/paper and are planning on using Maple TA as our primary homework & assessment tool in our math classrooms. Therefore, I have been writing anywhere from 20 to 50 questions per chapter, and our current Algebra I book has 12 chapters so you do the math.

Hello How can i have just 1 instance of Maple opened. Because when i open an worksheet (with the .mw extension), another copy of the Maple main program opens which is RAM consuming. THX

In the Maple 11 user manual, at the beginning, on page 1 is an integral of sin(1/x)dx from zero to pi. The solution is given as an expression including -Ci(1/Pi). No definition or explanation is given for Ci. So my obvious question is what in the world is this Ci? I suspect it is a constant but if that is true, why doesn't the program present it's value? Then on page 20 is another integral where the answer is given as 1/2 erf(1)sqrt(pi). Here again, there is no explanation of what in the world erf(1) means, so what in the world is erf(1)?