hi

I need your help,it is very necessary.I want to write two dimensional arrays to a file ,and then I should be able to read it again.I appericiate your help.

Hi!

I seem to run into problems with (quantum) perturbation theory. In the following minimal working example, an energy denominator, as occuring in perturbation theory is not evaluated if I previously assume that the quantum number is a positive integer. It's supposed to return an error, as the energy denominator is 0.

Download energy_denominator.mw

Best regards,

Sören

how to calculate the cobordism between two ideals

Hi,

I was helping for a computing session today.

Maple 17 and 18 were not plotting the following:

restart:

with(plots):
spacecurve([x,cos(x), sin(x)], x = 0..10);

On some of the machines, with campus site license, windows 7, x64.

The plot came up with a "frame" only. And nothing was plotted.

We really can't figure out why?

Something to do with the settings(options)?

Had anyone had a similar experience?

Thanks,

casper

for example, how to convert below word relation into graph

a^2 = 1

a*b = b*a

So I'm trying to make a procedure to tell is a sequence is graphical or not.
seqgraph:= proc (L::list)

local k::integer, i::integer, n::integer, a::integer, S;

n := numelems(L);

S := convert(L, `+`);

a := 0;

if type(S, odd) then print("not graphical")

else for k to n do

if add(L[i], i = 1 .. k) <= k(k-1)+add(min(k, L[i]), i = k+1 .. n) then a := a+1

else a := a+2

end if;

end do;

end if;
if n = a then print(graphical)

else print("not graphical")

end if;

end proc;

 I'm trying to say that if that equality (which is part of the erdos gallai theorem) holds for that value of k then we'll add one to a value (a). Thus, if a=n at the end then the ineuqality was true for each k and thus it would it should print "graphical" but every list I test it one prints 'not graphical'. Where is my mistake? I get an error saying it can't execute add?

From some scientific experiments, the following set of data is available
(1.0, 2.33),(2.0, 0.0626),(3.0, −2.16),(4.0, −2.45),(5.0, −0.357),(6.0, 2.21),(7.0, 2.75),(8.0, 0.636),(9.0, −2.45).

We need to use least squares method to fit the curve to the data
y = a + b cos(x) + c sin(x) + d cos(2x) + e sin(2x)

Show your solution procedure in Maple and get the best fit for the coefficients. Finally
plot the data and the y curve together on the same graph to visualize the fitting. For the
data, use blue circles while for the y curve, use red solid line style. Use the leastsquares
command we learned in LinearAlgebra package.

What is the solution to the following system? Is the solution unique? Use
the reduced row echelon form to explain why.
x + 2y + 3z = 1,
4x + 5y + 6z = 1,
7x + 8y + 9z = 1

Find the eigenvalues and eigenvectors for

A =
2 0.37 0
0 1.1 −4.29
1.6 0 2.2

Can you estimate the largest eigenvalues (in absolute value) using Power method for this
problem? Try to explain why if you can

Find the quadratic polynomial which interpolates (2, 0),(6, 1),(8, 0). Solve this with Maple. Start the problem by setting f(x) = ax2 + bx + c for example, then the unknowns are a, b, c.

If I have a list, how can I write a program to see is that list is graphical? So far I have

graphicalseq := proc (L::list)

local i::integer, N;

N := convert(L, `+`);

if type(N, odd) then print("Sequence is not graphical")

else if numelems(L)-1 < L[1] then print("Sequence is not graphical")
end if;

end if;

end proc;

I know I still have to keep going to determine whether the sequence is graphical, but I'm not sure how.

 I was thinking of trying to somehow use Havel-Hakimi's theorem, but again I'm not sure how. Any hints would be appreciated.  I can't use the is Graph Sequence function

How can I find stepwise solution of the following integral?

Int(exp(-xi^2*b^2)*cos(xi^2*a*t)*cos(xi*x), xi = 0 .. infinity)

where xi greek letter.. 

Here was my search strategy to find the answer:

keyboard shortcut execute worksheet on http://www.mapleprimes.com/search/?term=keyboard%20shortcut%20execute%20worksheet

only found one thing http://www.mapleprimes.com/users/erik10/answers

Googled it found 

http://www.maplesoft.com/support/help/maple/view.aspx?path=worksheet%2Freference%2Fhotwin

http://www.maplesoft.com/support/help/Maple/view.aspx?path=worksheet/expressions/executeworksheet

http://scipp.ucsc.edu/~haber/webpage/maple_cheatsheet.pdf

Don't see a keyboard shortcut. 

What is the keyboard shortcut to execute entire worksheet? Is there a name for this action of executing the whole worksheet? 

What did you search and click to find the answer? 

Hello everybody,

I find a answer on that subject at this link: http://www.mapleprimes.com/maplesoftblog/95508-Monte-Carlo-Pi

But for starting easy, I try this:

with(RandomTools[MersenneTwister]);
directpi := proc (n)
local i, x, y, N;
N := 0;
Digits := 2;
for i to n do
x := GenerateFloat();
y := GenerateFloat();
if x^2+y^2 < 1 then
N := N+1:
end if:
end do:
N;
end proc;

evalf(directpi(4000)/(1000.0), 4);

                             3.176

I would like to know if this code is appropriate and if it is possible to have a random number between -1 to 1 so it will be easier to plot the points in the square with the circle inside.

Thank you.

--------------------------------------
Mario Lemelin

Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987

I am Maple 15 student edition user and the packages is not loaded when I use the execute all command from the GUI. I have to manually press the enter key to have by package loaded before I use a function defined in the package. How can I work around this issue?

Thanks

P.S: You can see the Maple document attached to this post.

NumericalSimulation.mw