Hi all,

I am trying to do some calculation using Maple. I have different expressions containing some power of y. I would like that Maple automatically substitutes y^4 = f(y), in each one of these. So for example, if my expression contains y^5, I want it substituted by y * f(y), and so on. How can I do?

Hi all,

I'm trying to perform some calculations containing exponential integrals. Here is a snippet of my code:

restart;

H:=0.5:

q[0]:=10^5:
Es := 4*10^9:

p[0]:=10^6:
q[s]=10^10:

C := (q) -> q^(H+1.5):

G := (q) -> (int(q^3*C(q), q = q[0] .. q)):
P := (q) -> 1/sqrt(G(q)):

p := (xi) -> p[0]/P(xi*q[0]):
w:= (q,xi) -> 1/(Pi*(int(C(qs)*qs^3, qs = xi*q[0] .. q)))^(1/2):

U := (xi) -> (int(q*C(q)*w(q,xi)*(Int(exp(-(w(q, xi)*ps/Es)^2)/ps,ps=p(xi)..infinity)),q=xi*q[0]..q[s])):

My objective is to evaluate U for a set of discrete values of xi for further processing e.g. visualisation via plots. Neither value(U(xi)) nor evalf(U(xi)) produces a numerical result so I keep searching for solution. Does anybody have an advice how to solve U?

Regards, lassa

Hi, I have defined two functions:

ex1 := (x,t,z) -> -1.132*10^(11)* exp(9.9*10^(6)*x)*exp(sqrt(-1)*(1.95*10^6*z-2.98*10^15*t))

ex2 := (x,t,z) -> -2.82*10^(12)* exp(2*10^(6)*sqrt(-1)*x)*exp(sqrt(-1)*(1.95e*10^(6)*z-2.98*10^(15)*t));

And then tried the command:

implicitplot3d( ex1, x = -10..0, t = 0..10, z = 0..10, axes = boxed, style = patchcontour, scaling = constrained, shading =z);

But the boxes are entirely blank! What is the problem here?? It should be some kind of sine curve

Maple 2016.

Why does

int(sqrt(c+d*tan(e+f*x))*(a+b*tan(e+f*x))^(5/2),x);

Causes mserver.exe to hang into a loop at full CPU and maple hangs?

Windows 7, 64 bit.  Even using timelimit() on it, it still hangs exceeding the time limit and never return. I have to kill mserver.exe or exit Maple to recover.

A quick question, Can I add legends to 3D plots? 

I am currently working in Maple, following an example on the Maplesoft site very closely. I am trying to make use of the 'Colorize' function in the Escape-Time Fractals package.

I have a Newton's basin with the standard colouring but am trying to make my image more sophisticated. I have tried following the example given for the Mandelbrot set (At the bottom of the page - http://www.maplesoft.com/support/help/Maple/view.aspx?path=Fractals/EscapeTime/Mandelbrot) as there isn't one on the Newton Fracal page but keep receiving the Kernel lost message. I do not think the issue is my firewall.

My code is as follows,

with(Fractals:-EscapeTime);

with(ImageTools);

Everything works up until I go to evaluate P. I have tried giving both Arrays datatype=float[8] and have tried getting rid of the datatype section completely as to use the default. Neither of these have helped.

Any insight as to why this may be happening would be appreciated.

Hello,

I have to calculate the eigenspace of a bunch of matrices and then intersect all together. Is it possible to have a procedure for this problem that returns a basis for the intersection of all the eigenspaces?

My matrices are tensor products of matrices so I was wondering whether there is a procedure to calculate the kronecker product of more than 2 matrices.

Thanks!

Hello,

Paraphrasing:

https://en.m.wikipedia.org/wiki/Langford_pairing

given a sequence of 2n numbers 1,1,2,2,3,3,...n,n in which the two 1's are 1 slot apart, the two 2's are 2 slots apart, the two 3's are 3 slots apart, -> generally the two n's are n slots apart.

for n=3, a possible sequence is [2,3,1,2,1,3]. 

There is sequences for n=4,7,8...

i havent a clue how to write a maple procedure to generate a sequence for given n, but I'm hoping an expert here can.

Good evening,
I know the plot package and use frequently, but the basics. Now I need to make a curve that looks like an " umbrella " and it appears the projection in the xy plane . I don't know if it's possible , but I'm not getting . Does anyone have any idea to help me ? Thank you!

I'm trying to write a procedure that computes Pollard's P-1 Method for a given integer n, and then outputs the prime factorisation of n.

Here is what I have so far:

Pollard := proc (n)
local i, r, g;
r[1] := `mod`(2^factorial(2), n);
for i from 2 while gcd(`mod`(r[i-1]-1, n), n) = 1 do
r[i] := `mod`(2^factorial(i+1), n) end do;
g[i] := gcd(`mod`(r[i-1]-1, n), n);
if g[i] < n then return g[i]
else return n
end if
end proc;

But my procedure doesn't seem to work for a lot of large values for n.
And also I can't figure out how to make it actually output the factorisation.

Any help would be appreciated.

Maybe this is trivial but could somebody tell me how to get bounds of interval returned by shake? For instance,

shake(sqrt(2)) gives INTERVAL(1.41421356167 .. 1.41421356308), and I would like to store the upper and lower bounds as rational numbers in two variables. 

Hello,

I would like to ask you for your help

I receive this message when trying to export matrix to excel file:

> restart; with(ExcelTools); with(LinearAlgebra);

> C := Import("C:/SourceFile.xlsx", "Overview", "AK51:CB94");

> C := convert(C, Matrix);

> B := Import("C:/SourceFile.xlsx", "Overview", "G3:G46");

> B := convert(B, Matrix);

> IM := IdentityMatrix(44, 44);

> NP := 1/(C-IM).(-B);

> NP[6, 1];  //check if there is value. Yes, it works.

> Export(NP, "C:/ResultFile.xlsx", "Sheet1", "A1");

Thank you for any help.

I have posted long time ago a patch for Shadebetween and you have transformed it into a hot fix:

http://www.mapleprimes.com/questions/205956-Error-In-Shadebetween

In the last Maple 2015 update, the problem was not fixed.

Just curious: is it fixed in Maple 2016? Because I feel that the Maplesoft team is not "impressed" by such patches.

Edit. This was a comment related to acer's patch for NLPSolve, but it was transformed (I don't know why) into a separate question.

@Carl Love 

i guess that it is this.

actually my goal is 

drawing

 tangent vector field on even-dimensional n-spheres

can vector field plot do this too?

if start from draw vector field on a sphere

i find that intersectplot under plot, 

is it possible for fieldplot has this

such as the graph in wiki

https://en.wikipedia.org/wiki/Hairy_ball_theorem

how draw a line x+y = 1 on a sphere x^2+y^2+z^2 = 1 in maple