Hello all, 

Would you allow me to ask this one question?
[moderator: See also this previous question]

Is there any possible way to treat the differentiation operator (e.g., 'D') as an ordinary coefficient of a polynomial?

For example, as described in the attached worksheet, I was wondering if there is a way to re-write the LHS of the expression 'eq_e5_9b' as the expression 'desired'. 

In Kwon Park 

Download Q20220404.mw

How do I create a pointplot with different values of a parameter?

I tried

pointplot([seq([k, a(k, a0)], k = 0 .. 10, a0 = [0, 50, 100, 150, 200])]);
Error, invalid input: seq expects its 3rd argument, step, to be of type numeric, but received a0 = [0, 50, 100, 150, 200]
NULL;

ImportGraph reads one or more graphs from a file. For a file containing multiple graphs, the supported formats are digraph6, graph6, and sparse6. I notice that one option is "output = graph or list, or iterator". However, in my programming with Maple, I was reminded several times that list is only good for a small amount of data.  

Although I can convert the list to an array using the convert function, the time spent in the conversion process needs to be considered.

restart: 
with(GraphTheory):
L:=ImportGraph("C:/Users/eul10c.g6", graph6, output=list):#31026 connected eulerian graphs on 10 vertices graphs and Change to your path here.
convert(L,Array) 

So does it make more sense to provide an "output=Array" as an output option?

eul10c.txt

I am trying to decide O of times fo a computer process. I thought it was n^2*log(N) or something like that.

With 12  points, it may be hard to determine if O(N^4), etc.

See big-o.mw

When resizing a textplot the text is not scaled. 

I am trying to use "solve" to solve a set of 2 equations defined by using summation function "sum". But I got an error saying "Error, (in sum) summation variable previously assigned, second argument evaluates to 3 = 1 .. 2". 

The Maple code is listed here

restart;
N := 2:
var:= seq(alpha[n], n = 1 .. N):
v(x):=sum(alpha[n]*phi[n](x), n = 1 .. N):
R(x):=diff(v(x), x $ 4) - p/EI:
eqs := seq('int'('R(x)'*phi[n](x), x = 0 .. L) = 0, n = 1 .. N):
for n to N do
    phi[n](x):= sin((2*n - 1)*Pi*x/L):
end do:       
solve({eqs}, {var});
Error, (in sum) summation variable previously assigned, second argument evaluates to 3 = 1 .. 2

Hi,

While playing with this, I got:

> sum(Beta(k,1/2)/(2*k+1)^2,k=1..infinity)
Error, (in SumTools:-DefiniteSum:-ClosedForm) summand is singular in the interval of summation

I don't see how this can be singular, as Beta(k,1/2) is trivially bounded for k>=1, and sum(1/(2*k+1)^2) is absolutely convergent.

Maple is still able to evaluate numerically the inert sum (I get 0.3361376233). If I replace Beta with the expression with GAMMA, I get a result with MeijerG, that doesn't seem to help much for numerical evaluation, as it takes a long time and gives the wrong result -1.966769953*10^10 - (6.886827095*10^8)*I.

I have no reason to expect a closed form for this sum, but the error is surprising. And I don't know MeijerG well enough to explain the numerical error either. It fails with Maple 2020, 2021 and 2022.

Hi,

I try to animate the tangent in a moving point on the curve

ideas ?

Thanks

QuestionAnim.mw

Hey, I've got simmilar problem. I will show it on the same example, but here my expressions are defined as functions and both graphs should be on the same plot. With my version I get:

Warning, expecting only range variable x in expression a*x^2 to be plotted but found name a

My version is:

;

Version below works fine, but I wanted to have this plot in a worksheet not in popup window:

Thanks in advance,

Iza

I try to simplify the expression by putting exponential function into equation but the maple shows error which I can't fix it.simplification.mw

Hi,

I am trying to use Maple to solve a PDE involving composite functions.  How do I program this?  Here is an attached file describing what I am trying to do.

Partial_Differential_Equations_of_Composite_Functions.mw

Hi I was trying to difine a constant c that exists in range(0,d). The constant c has two values and is depends on its x location.  The first value "a"  has a duration "e" , the second value "b" has a duiration "f". Start from x =0, the constant c has value "a", then "b", then "a"......

 How should I define this constant in "piecewise"?

I have the following example.

> A:= Vector(3,symbol=v)

A:= 

>v[1]:= 5

v[1]:=5

> A

Is there any way such that v[1] is actually referring to the first element in the vector? In other words, changing v[1] actually modifies the vector A.

If the question does not make sense, then here is the actual scenario that I faced.

I need to solve a system of equations in the form of 

where a[i], c[i] refers to the entries in the vector.

solve returns the following:

I then did an assign(%). However, the entries in A and C are not changed. I want the answer returned by solve to be properly applied to the entries of the vectors.

I have been trying to integrate the following an expression using Maple's command PathInt:

PathInt(4*x*y*(y^4+2*x*y-2)/sqrt((1-(2*x*y)^2+(-3*y^2+1)^2)*(1+(y^2-1)^2)), [x, y] = Path(`<,>`(-(1+sqrt(2))*cos(t)-(sqrt(2)-1)*sin(t), cos(t)-sin(t)), t = 0 .. 2*Pi)).

However, Maple does not return a result, but rather an integral. Is there an alternative way to solve the integral above?

Thanks in advance.