Hello everyone, I recently learned how to plot vector fields using maple. So far, I know of two ways using VectorField(output = plot) and fieldplot3d(some_vectorfunction). My problem is that, it seems these two functions yield slightly different plots, fieldplot3d seems to give a more accurate depiction of the actual vector field, whereas the other function gives a similar ouput but in a more 'sloppy' form. Is this normal? Or am I doing something wrong?

Here are the two plots done by each function:

fieldplot3d:

VectorField(output = plot):

Hello,

I would like to symbolically determine the rank of a jacobian matrix. In the help, I have seen that the Rank function of the LinearAlgebra can be used for this purpose. However, when I use this function, the function doesn't allow to find the different singularities that can occur on my jacobian matrix.

Here a exemple of a jacobian matrix that I obtain on a slidercrank mechanism:

The rank of this jaobian (Phi) gives 2 whatever the values of theta(t) and beta(t). However, if the values of  theta(t) and beta(t) are :theta(t)=Pi/2,beta(t)=0. The rank shouldn't be 2 but 1.

Is a way to obtain the symbolic calculation of the rank of a jacobian matrix which can distinguish different cases following the values of the parameters ? In others words, my dream will be to have a Rank function (or another algorithm) which can gives :
the rank is 2 if theta(t) different of Pi/2 [Pi] and beta(t)=0 [Pi] 
and otherwise 1 if ...
and perhaps 0 if ...

Thanks a lot for your help.

I let a piece of code with an example of calculation of the rank

RankMatrix.mw

I am trying to solve the folowing ODE with initial conditions t0=0,v0=0 and tf =80 with step 0.01 but the matrix that appears is not having the values!please help

Download runge_kutta4.mw

Is this what is supposed to happen when linking Maple to Matlab?  I was hoping it would open the actual Matlab program and write variables to the current worksheet.  I'm I missing something?

Nothing even pops up on the Matlab Command window. What good is this?

Hi 

I have 3 equations

eq1 := vs = (Rs+Z)*i1+Z*i3

eq2 := A*vi = Z*i1+(Z+Rf+ro)*i3

eq3:= vo = (Rf+Z)*i3+Z*i1

and I want to solve for vo/vs . How to do that ?

the expected solution is 

For bonus in my one class, we are required to change the code in a program to have it produce another row when running Neville's Method. We need to, after it runs initially, have it ask "Run another time? Y/N" and type 'Y' or 'N' for Yes or No. If No, it ends the program. If yes, we need to have it input another x(i) and f(x(i)) without having to input all the other data points again. Here is what I have so far (this is just the additional part we have to add, not the whole code):

 print(`Do you want another point? Type Y or N.`):
  J := scanf(` %c`)[1]:print(`Entry = `):print(J):
  if J = "Y" or J="y" then
  AGAIN := "Y":
  AGAIN = "Y" or AGAIN = "y":
        OUP := default:
      fprintf(OUP, `NEVILLE'S METHOD\n `):
       fprintf(OUP, `Table for P evaluated at X = %12.8f , follows: \n`, X):
       fprintf(OUP, `Entries are XX(I), Q(I,0), ..., Q(I,I) `):
       fprintf(OUP, `for each I = 0, ..., N where N = %3d\n\n`, N):
       for I1 from 0 to N+1 do
         fprintf(OUP, `%11.8f `, XX[I1]):
         for J from 0 to I1 do
           fprintf(OUP, `%11.8f `, Q[I1,J]):
         od:
         fprintf(OUP, `\n`):
        od:
    if J="Y" or J="y" then
         AGAIN := Y:
             if AGAIN = Y or AGAIN = y then
                 #N=N+1:
                  if N > 0 then
                  OK := TRUE:
                 for I1 from N to N+1 do
                        print(`Input X(i) and F(X(i)) for i = `):print(I1):
                        print(`separated by a space `):
                       XX[I1] := scanf(`%f`)[1]:
                       Q[I1,0] := scanf(`%f`)[1]:print(`Entries are`):print(XX[I1],Q[I1,0]):
                  od:
                else
                  print(`Number must be a positive integer `):
               fi:


            else
                AGAIN := No:     
         fi:
         fi:
    else
        print(`Ok thanks`):
 fi:

Not sure what I am doing wrong and any help is appreciated. Thanks.

Leading on from this post I made before:

http://www.mapleprimes.com/questions/210359-Integrating-Very-Large-Sums

I have a script that can now integrate larger sums thanks to the tips I was given. I now have a question regarding cpu usage when the calculation is run through a loop. I have attached two files. One contains the sum (large_sum.txt) which is then read in to the main Maple script (large_sum_int.mw).

When the loop is run, the first few points are calculated quite consistently with very similar cpu times. However, as the calculation progresses the cpu time suddenly increases (with larger sums than the one given it is a very severe increase) it then decreases again and returns to the time it took for the initial points to be calculated.

Is there a reason there is a sticking point in this calculation? is there a more efficient way to simplify it before it reaches the integration stage? When using simplify(...,size) the initial block takes a very long time to execute hence is not included here. This is not the largest sum that needs to be processed so I am looking for means to speed up calculation time/make it more consistent.

Any help is appreciated

large_sum.txt

large_sum_int.mw

-Yeti

I have to use the optimization package. 

- The objective function is non linear,

- I have constrains and bounds,

- The constrains are not linear.

I have reading the help page on maplesoft.com

My question are:
Can you confirm me that the only algorithm I can use is : NLPSolve with method ''sqp''?


And if I would like to use the gradient method how can I do?

This is somehow an old problem which came back and I decided to post it. So, I have some code which runs in Grid framework locally. Each node saves data directly to hard disk and there is no need to return anything at the end to the node of ID 0. Nevertheless, I noticed that memory usage on one instance of the mserver is very huge.  Moreover, this instance is all the time in S state, namely sleeping. Below you can see dump from top. I deny this is caused by some particular procedures called in my code since in this case I should rather observe more uniform memory usage. I am not sure if for this moment I could share some code with you which demonstrate this behavior. I will try to write some toy example because my productive code cannot be posted here.

%MEM     TIME+ COMMAND

49.1 17:00.19 mserver
0.1 12:43.70 mserver
0.1 12:32.15 mserver
0.1 13:54.02 mserver
0.1 14:45.45 mserver
0.1 12:35.22 mserver
0.1 13:50.77 mserver
0.1 14:14.85 mserver
0.1 8:58.82 mserver
0.1 12:58.48 mserver
0.1 8:51.00 mserver
0.1 10:35.92 mserver
0.1 12:58.13 mserver
0.1 9:34.39 mserver
0.1 10:10.13 mserver
0.1 12:07.77 mserver
0.0 8:21.17 mserver
0.0 11:41.42 mserver
0.0 5:07.27 mserver
0.0 8:31.88 mserver
0.0 6:30.12 mserver

What is the maximal independent set of monomial ideal$<c^4a^3b>$ in $K[a,b,c]$?

Hello,

In the creation of a list, I would like to use the assume function twice.

Here it is a print screen of my issue.

The second part of the list is not taken into account.

Do you have ideas so that my list takes into account the second term ?

Thanks a lot for your feedback

not the same ordering every time of monomials after determinant and map sign positive and op in maple 15

sometimes i need to use Reverse or Rotate List to adjust.

why ordering is different in list of monomials?

is it caused by virus?

Hi there. 

I have a equation following:

with letters {a,b,c,d,k} is missing all solutions ,but with {z,u,w,t} letters works fine.

--------------------------------------------------------------------------------

Bug_maple.mw

I_Mariusz

Hi everyone, I got a problem. I'm a new user and I'm getting to know this beautiful software.

The problem is that when I enter a function in math mode (the easyest with simple inputs I guess), once I right click and plot only the cartesian plot is shown, without the actual function. 

What should I try? Math without plots is boring... :)

Thank you!

I have the following question:

Illustrate how the sequence N->R defined by n ->n^2/n^2 + 31n + 228 can be shown to be
within a given epsilon > 0 of its limiting value x0.
(a) use an appropriate conditional statement to find N such that abs (xn -􀀀 x0) < epsilon for every n>=N
and produce an appropriate list of the data points (n,xn) to illustrate
this

I found N but without using any CONDITIONAL STATEMENT.Can you help me find N using IF FOR WHILE?