I need to write a procedure that returns the cut vertices of a graph, but I think I'm having trouble defining my local variables. This is what I have so far.  I think my error might be in defining H since that's the line the error message I get keeps referencing.  Am I defining H incorrectly or in the wrong spot? Any advice would be appreciated. Thanks

cutvertices := proc (G)

local numvertices::integer, currentvertex, i::integer, H;

description "Returns a set of all the cut-vertices of the given graph";

numvertices := nops(Vertices(G));

for i to numvertices do

currentvertex := Vertices(G)[i]

H:=DeleteVertex(G, currentvertex)

if nops(ConnectedComponents(G)) = nops(ConnectedComponents(H)) then print(currentvertex)

end if;

end do;

end proc:

When I open my file I got an error message says "there were problems during loading process"

and some of my text are missing.

Maple Worksheet - Error

Download quant_hw_5.mwquant_hw_5.mw

Download quant_hw_5.mw

Can anyone help me,please

i want to solve an equation by fsolve but i cant assign a value as an input for next step!

please help me

s := fsolve(G), x = -1 .. 1     

s := .1449607418, x = -1 .. 1  

 a:=s+1  

Error, invalid input: subs received .1449607418, which is not valid for its 1st argument                  

Hello everybody. I'm newbie and my english are not very good. Please help me debug an error in my files DSOLVE_NOT_SUCCESSFULL.zip: "Error, (in ans) cannot determine if this expression is true or false"
Thanks.

See AAAA.mw

The alpha and beta are 'randomly' chosen, both >0, to produce some values, hence a value for the target function to optimize.

I am having trouble to evaluate the expression in the middle of the calculation.

Sometimes, the 'chosen' alpha and beta works fine with 'method = _d01amc' for numerical integration. and such way is really "fast".

But sometimes, the the 'chosen' alpha and beta will fail. Even when both of them are perfectly defined. and the integral can be easily evaluated using Int() and then evalf().

So what's be best way to proceed?

Thanks,

casperyc

Consider the following sum:


We know that if k is between 1 and N, the result will be



and otherwise the sum is zero.

How can I tell maple to compute this sum in each case without giving numerical values to the parameters "N" and "k"?

Thanks. :)

If I were to evaluate a single numerical integral, I can use evalf( Int(,method = _d01amc)).

But when the expression say is created by a built in function, Student[VectorCalculus][Hessian], from a complicated expression involve integrals. The resulting expression does not have the option "method = _d01amc". It then takes a long time to evaluate.

See this "HE" variable for example. HE.txt

value(HE); # takes a long time

evalf(HE); # takes a long time

Is there a way to evaluate "HE", using ",method = _d01amc" wherever necessary?

Thanks!

I'm doing some stuff with Taylor Polynomials on Maple. In particular, I'm trying to find the second order Taylor Polynomial of e^x cos x. I'm using the "taylor" command.

This is what I have so far:

> f := proc (x) options operator, arrow; exp(x)*cos*x end proc;
x -> exp(x) cos x
> s2 := taylor(f(x), x = (1/3)*Pi, 2);
> p2 := convert(s2, polynom);
1 /1 \
- exp|- Pi| cos Pi
3 \3 /

/ /1 \ 1 /1 \ \ / 1 \
+ |exp|- Pi| cos + - exp|- Pi| cos Pi| |x - - Pi|
\ \3 / 3 \3 / / \ 3 /
> y1 := evalf(subs(x = .5, f(x)));
0.8243606355 cos
> y2 := evalf(subs(x = .5, p2));
-0.208092943 cos

Everything looks fine until the last two lines.

How do I interpret ".8243606355*cos" ? Cosine should have an argument. Am I messing up something with my code, or is this standard in Maple language?

Hi all,

Assume that we have a vector, namely v:=[1,-2,3,-4] and we want to construct special matrix namely Z, from Vector v as follow:

first row is 1, secnond row is -2,..., the end row is -4 namely
Matrix([[1,1,1,1],[-2,-2,-2,-2],[3,3,3,3],[-4,-4,-4,-4]]);

in the other word every row of matrix is 4 times corresponding componet in vector.(for example v is (1*4))

how can we do this?

best wishes

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

n=512, what is number = nops(T) without actual running code?

n := 512;
T := [];
for i from 1 to n do
for j from 1 to n do
if i < j then
for k from 1 to n do
if j < k then
T := [op(T), [i,j,k]];
end:
od:
end if:
od:
od:
nops(T);
T;

Good day everyone, please help in writing finite difference algorithm for these coupled nonlinear ODE. See it here Algorithm.mw 

As title.

While  I can  decide velocity,charge and Distance.

Hi

I have three system of ODE and i would like to solve it using Homotopy perturbation method. Could you please provide to me the code in Maple or the Maple pachage that used to solve it by Homotopy perturbation method ?

I hope to hear you soon

Sara

Hi there. 

I'm kind of new to Maple and i'm trying to solve a Linear Algebra problem for my class of Linear Algebra of the course of Physics. Also, my first language is portuguese so forgive for my not-so-perfect english.

I have a (solved) linear system of 7 equations and 12 variables (A, B, C, D, E, F, G, H, I, J, K, L) that is the following:

• A = 33 - K - L
• B = 1 + F - J
• C = -15 - F + J + K + L
• D = 15 + H - K
• E = 16 - F - H + J + K
• G = 34 - H - J - L
• I = 18 - J - K

Note: I'm using letters (A, B, ..., L) instead of X₁, X₂, ..., X₁₂ because it's easier to write it like this here and because I don't know if the X_n notation is allowed on Maple (i don't think so).

So, the system is possible but undetermined (with 5 degrees of freedom), being F, H, J, K and L the free variables.

Until here, everything's fine. The problem arises when the professor asks us for every solution of the system that satisfies the condition that all the variables (form A to L) are positive integers (A, B, C, D, E, F, G, H, I, J, K, L ϵ IN → natural numbers).

From my understanding, that gives rise to a system of linear inequalities with 12 variables and the following inequalities:

• A = 33 - K - L > 0
• B = 1 + F - J > 0
• C = -15 - F + J + K + L > 0
• D = 15 + H - K > 0
• E = 16 - F - H + J + K > 0
• G = 34 - H - J - L > 0
• I = 18 - J - K > 0
• F > 0
• H > 0
• J > 0
• K > 0
• L > 0                            (and A,B,C,D,E,F,G,H,I,J,K,L ϵ IN)

After some research, i found that a possible way to solve this type of system of linear inequalities is trough a method of elimination (analog to Gauss-Jordan's elimination method for systems of linear equations) named Fourier-Motzkin. But it's hardwork and i wanted to do it on the computer. After some research, i came across with the following Maple command:

SolveTools[Inequality][LinearMultivariateSystem]

http://www.maplesoft.com/support/help/Maple/view.aspx?path=SolveTools%2fInequality%2fLinearMultivariateSystem

So, I tried to use that command to solve my system, with the following result (or non-result):

with(SolveTools[Inequality]);
LinearMultivariateSystem({F > 0, H > 0, J > 0, K > 0, L > 0, 1+F-J > 0, 15+H-K > 0, 18-J-K > 0, 33-K-L > 0, 34-H-J-L > 0, -15-F+J+K+L > 0, 16-F-H+J+K > 0}, [F, H, J, K, L]);

Error, (in SolveTools:-Inequality:-Piecewise) piecewise takes at least 2 parameters


So, i really need help solving this as the professor told us that the first one to solve would win a book, eheh. I don't know what I'm doing wrong. Maybe this Maple command is not made for 12 variables? Or maybe i'm just writing something on a wrong form. I've never used Maple before so i can be doing something really stupid without knowing it.

I would really apreciate an answer, as my only goal as a future physicist is to unveil the secrets of the Cosmos to us all.

Thank you again.

Miguel Jesus

This application calculates the number of photons reaching a camera sensor for a given exposure. A blackbody model of the sun is generated. The "Sunny 16" rule for exposure is demonstrated. Calculations are done using units.Photon_Exposure_Array.mw

Download Photon_Exposure_Array.mw