Hello

I've written a completely symbolic expression involving sum function. When I hit enter, Maple 2016.2 evaluates the expression although it's completely symbolic and not evaluable.

How to stop Maple from falsely evaluating a symbolic expression? I dis use the restart command to make sure all variables are empty. When evaluating Maple generate a very large open form expression that makes no mathematical sense.

Maple file in the following link

https://www.dropbox.com/s/13ciwothh1pqijk/sumBug.mw?dl=0

Please advice

Thanks

I am fairly new to Maple and I'm currently researching twisted multiloop algebras. I'm trying to use Maple to automate many of the calculations. For example, suppose xy = yx + 2z and I have the expression wxy (the variables are non-commutative. I already have this functionality working properly with the physics package). I want Maple to make the substitution for xy and simplfiy. For example: wxy = w(yx + 2z) = wyx + 2wz. Is this possible?

Thank you for your help.

I have two matrices, one of the dimension of solution space that i have been using solve to navigate
this matrix will look something like:

M := matrix([[3, 2, 1], [2, 1, 1],[2, 1, 1]])

and I have another matix of the times that it takes solve to find these regions:

N := matrix([[.2, .4, .8], [.3, .6, .5], [.8, 2.3, 2.6]])

I'd like to find the sets {N[ij]:M[ij]=m for some integer m}; that is I'd like to get all the elements of N on entries of M with the same number so i can start thinking about them statistiaclly.

i.e. for 3 i'd like the list [.2]

      for 2                      [.4 .3 .8]

and so on.
 

I wish to extract a minimum route in a network given both start and end positions.

Also, I wish to avoid a spur in the circuit and obtain one continuous orthogonal  path. 

As an example, take the 7-node case having 14 arcs (see worksheet) using Dijkstra's algorithm (I assume this is fit for purpose in this particular case).

Starting with node 1, the algorithm suggests the paths:

1>2>3>4>5>6>7.>8>9 and 1>2>3>4>5>10>11>12>13>14 (here, there is a spur at node 5 where the paths separate)

Is it possible obtain one minimum path?

The source node is prescribed in the routine - can anyone explain how to prescribe the end node?

Thanks for reading!

Shortest_Circuit.mw

I tried to integrate

int((1-x^floor(u))/((1-x)*u^2), u = 1 .. infinity, numeric)

where x=-1. The result should be log 2 = 0.6931471806. However it gives me 0.6687714032.

When using a numeric cut off, the result improves, so what is the issue here?

6687714032

Hello.

I have this problem when executing the entire worksheet or selected groups.
Also Maple can crash by itself, to its heart's content)
What I can do to solve this problem?
OS: W7 x64, Java is up to date

Thx.

Hi Guys i need some Help. 

I created a work sheet where i am calculatin the polynominial coefficient of an equation. The Problem is that if i take these coefficient and then calculate the root with Matlab and compare it with the symbolic toolbox  i get wrong roots. My question now is did i something wrong by creating the coefficient ? 

Polynom_Calculation.mw 

These are the values for the parameters : 

b1=0
b2=0
v1=0
v2=0
s1=0
s2=0.175
j2=0.28
tau =20
th1 = 0
th3 = 0
 

i added  my Maple skript. i hope that sb can help me.

In the first one I used hypergeometric function where the number is converged. Now using the series expansion of hypergeometric function I rewrite the equation as in the 2nd and 3rd case. But here it is not converging. I expect the same answer as in the first case i.e 0.14042. Thank you

problem2.mw

I have an 8*5 matrix, and i'd like to replace elements of it that are >20 with 20. For those interestedm, the matrix comes from this question.

M := Matrix(8, 5, {(1, 1) = 1.266, (1, 2) = .734, (1, 3) = .656, (1, 4) = .735, (1, 5) = 1.843, (2, 1) = 2.859, (2, 2) = 5.625, (2, 3) = 5.188, (2, 4) = 5.453, (2, 5) = 10.765, (3, 1) = 3.281, (3, 2) = 9.000, (3, 3) = 5.516, (3, 4) = 5.828, (3, 5) = 6.156, (4, 1) = 7.718, (4, 2) = 34.125, (4, 3) = 5.453, (4, 4) = 5.344, (4, 5) = 5.453, (5, 1) = 8.703, (5, 2) = 6.515, (5, 3) = 6.125, (5, 4) = 6.641, (5, 5) = 6.734, (6, 1) = 17.766, (6, 2) = 8.578, (6, 3) = 8.765, (6, 4) = 9.875, (6, 5) = 32.610, (7, 1) = 22.156, (7, 2) = 15.640, (7, 3) = 15.610, (7, 4) = 15.187, (7, 5) = 23.735, (8, 1) = 20.140, (8, 2) = 20.156, (8, 3) = 20.266, (8, 4) = 19.344, (8, 5) = 21.078})

I tried to create a logical matrix that i could input into M (this is how it works in maple) to select the elements so i could replace  them, but this didn't work 

Hello,  how can i  to adapt the  commands  below  to write  in fprintf a vector with  N components.

 fd≔fopen("temp_file",WRITE);

For exemple: Given a vector (or list)  v:=[1,2,3,4,....N], i would like to get  a file with  N column and 1 line, where N is a integer number, which i will give.

Thanks for any help.

(a) Plot the graph of  
                       sin(x)*exp^{( -x^2)}
 for x in the interval [-2,2]. 
(b) Find to 10 decimal digits the maximum and minimum values of 
                         sin(x)*exp^{( -x^2)}
 for x in [-2,2] AND find the corresponding values of x. [So if the maximum occurs at x=a, you should also compute sin(x)*exp^{( -x^2)}   both to 10 digits. Similarly for the minimum. Using unapply to make the expression into a function will be useful here.]  

So far I have this for a

> j := exp(-x^2)*sin(x);

> plot(j, x = -2 .. 2);

Generate 8 random 3 by 3 matrices using the RandomMatrix command from the  LinearAlgebra package. As each matrix is generated use Eigenvalues to compute its eigenvalues. Then take the product of the eigenvalues, and check that for each matrix, this product is equal to the determinant of the matrix.  

[Hint: The product will be complicated algebraically and you will need to apply first expand, then simplify to reduce the product of the eigenvalues to an integer. First try to do for a single matrix , then make a loop to do it 8 times.] 

There is a one-to-one correspondence between subsets of {1, 2, . . . , n} and binary lists of length n, that is, lists L = [x1, x2 , . . . , xn] where x1, x2, . . . , xn are elements of the set {0,1}.  The correspondence is given by associating to the set S the list L where xi = 1 if i is in S and 0 if not. For example, the set {1,3,5} corresponds to the list [1,0,1,0,1,0,0] if n = 7.

(a) Write a procedure list_to_set whose input is a binary list and whose output is the corresponding set. E. g., list_to_set([1,0,1,0,1]) will return the set {1,3,5}. Note that nops(L) is the length of a list.

(b) Write a procedure set_to_list whose input is a pair S,n where S is a subset of {1, 2, . . . , n} and n is a positive integer and whose output is the binary list of length n corresponding to the set S. E. g., if n = 5 then set_to_list({1,3,5},5) will return [1,0,1,0,1].

(c) Show by a few tests that each procedure works. Then apply set_to_list to each set in the powerset of {1, 2, 3, 4} to form all binary lists of length 4. Make a program to print out a table of the following form. (But the order need not be the same as that started below.)

   [0,0,0,0] <-->  {  }
   [1,0,0 0] <--> { 1 }
   [0,1,0,0] <--> { 2 } 
    ........
    etc

Some extra commas in the output is okay. You may obtain the power set of the set {1,2,...,n} by the command powerset(n); but you must first load the package combinat.

For each natural number n, the n-th square matrix  A_n is defined by 
                              A_n( i, j) =0 if  i = j,   A_n( i, j) =1 if i ≠ j
Carry out the following computations for n=3,4 and 5.

(a) Compute the determinant of  A_n

(b) Compute the characteristic polynomial of  A_n

(c) Determine all eigenvalues of  A_n and determine for each eigenvalue a basis of the corresponding eigenspace.