Dear Friends

            Hope everything going fine with you. I want the numerical solution of nonlinear system of ordinary differential equations using RK method. The system of ODEs and their required results are present in attached file. I am waiting your quick response.

Help.docx

With my best regards and sincerely.

Mob #: 0086-13001903838

I want to separate strings into substrings for example
input is "6,3,A,n,k,L,+,-" then the procedure breaks this string into substrings like 
if a member numeric b:="6,3",or if lowercase c:="n", if uppercase l:="A,L" else m:="+,-"
thanks

In the running of an example I faced to computation of radical ideal of the following ideal:

<-c*m*u+d*c*n+m*b*v+m*c*t>

I used from Radical command in PolynomialIdeals package. But I dno't now why it's computation is very hard and Time-consuming?

What I have to do? I think there is a bug, since this ideal is simple, apparently.

It took me a while to figure out what was causing this unusual sort result;

I loaded the MTM package because I want to convert numbers to integers for indexing. This sort result seem like it could be a bug.

Download MTMsort.mw

Hello Everybody,

I was trying to apply the Newton-Raphon method("Newton" in maple) for the following problem to obtain the constants (c1...cM) without success.

eq[1] := -0.0139687 c[2] - 0.0132951 c[1] = 0
eq[2] := 24806.4 c[2] - 0.0139687 c[1] = 0

If anybody has experience with it or knows how to use it I would really appreciate your help.

Just to introduce the previous steps of calculations leading to the problem:To calculate the critical buckling force N and the shape of a rectangular uniformly loaded plate the governing diff. equation is the following

D11*w''''(x)+(2*D12+4*D66)*w''(x)''(y)+D22*w''''(y)+N*w''(x)=0

For the follwing solution of a boundary value problem(Boundary conditions:clamped-clamped: w(x=0,x=a)=0 & w'(x=0,x=a)=0) I applied the Ritz method:

w:=sum(c[i]*(cos(2*i*Pi*x/a)-1)),i=1..M)

Thus the Potential Energy P is:

P:=16537.6*c[2]^2-0.0139687*c[2]*c[1]+1033,60*c[1]^2-9.86960*N*c[2]^2-2.46740*N*c[1]^2

 deriving P to each constant c and setting them =0 leads to:

eq[1] := -0.0139687 c[2] + 2067.20 c[1] - 4.93480 N c[1] = 0
eq[2] := 33075.2 c[2] - 0.0139687 c[1] - 19.7392 N c[2] = 0

After calculating N=418,902  and feeding eq1 and eq 2,the follwing equations if two terms are considered:

eq[1] := -0.0139687 c[2] - 0.0132951 c[1] = 0
eq[2] := 24806.4 c[2] - 0.0139687 c[1] = 0

Everything I tried resulted in any c1 = c2 = 0 which is not  realistic. Maybe I made a mistake earlier.

Thanks a lot in advance.

Sam

 Plate_Buckling.mw

Hi guys,

I can not execute any command in worksheet. I even can't set a variable to a number. When I write some lines and hit enter, it does not respond in anyway. Basicly I can't enter anything it doesn't do anything. How cold I solve this?

Hi

I've this equation ,what is displacement,

U := sum(C[i]*lambda[i]*h^2*M*(C[13]+C[55])*exp(Z*lambda[i]*M)*cos(M*x)/C[11], i = 1 .. 4);
 But when I used the data ,I do not get the right result

the datas are

h := .25;
M := Pi/L; L := 1;
E[3] := 1; E[1] := 40; E[2] := 1;
1
V[13] := .25; V[31] := .25; V[12] := .25; V[23] := .25; V[32] := .25; V[21] := .25;

G[44] := .2; G[55] := .2; G[66] := .2;

G[13] := .5;

C[55] := G[13];

Omega := -2*V[13]*V[21]*V[32]-V[12]*V[21]-V[13]*V[31]-V[23]*V[32]+1;

C[11] := (-V[23]*V[32]+1)*E[1]/Omega;

C[12] := (V[13]*V[32]+V[12])*E[2]/Omega;


C[33] := (1-V[12]*V[12])*E[3]/Omega;
 

C[1] := -.2596702449; C[2] := -2.411545729; C[3] := -0.6051254981e-1; C[4] := .4085627399;
 

lambda[1] := .6891428810; lambda[2] := -.6891428810; lambda[3] := 9.177422410; lambda[4] := -9.177422410;
 

could you help me plase

Limitation of Maple spreadsheet is only 100 x 52

I don't know why there's a limitation on the size but there's no way of increasing it either.  Is there?

Just to be sure that some outside operation wouldn't nudge the spreadsheet size I tried

with(Spread):
a:=CreateSpreadsheet():
b:=Matrix(100,100):

SetMatrix(a,b)
                           Error, (in Spread:-SetMatrix) spreadsheets cannot exceed 52 columns

So unfortunately until the feature gets built into Maple I don't believe there is a workaround.

I read research paper about elasticity, and I don't not how can get the results for displacment ant shaer stress,, could you help me please.

please help me

Kind Regards

hi.i encounter error in pdsole equations with unknown parameter(N)??

please help me for solve it....thanks alotmaple_prime.mw

Is it possible to assign both a value of zero to a variable and a unit? Maple seems to be ignoring the units when I do that.

For example:

a := 0atm

Becomes simply a := 0. My workaround so far is to declare a very small value, e.g.:

a := 1E-6atm

This keeps the units for the variable a. Note that 0 pressure isn't relevant here (the same happens for 0m).

Running Maple15 on a five year old lap top, complicated animations are taking up to 30 seconds as shown by debugopt(traceproc) followed by showstat.

Would a discrete video card e.g. Nvidia as opposed to an integrated video card significantly reduce these times or are such times primarily dependent on processor speed?

Hello

I have such problem:

I calculated rather complicated function, and i want to obtain the array or list of data with definite step.

For this purpose I used next expression:

Out:=[seq(t,F(t),t=0..tmax,step]

I need minimum 1000 points, but calculation for the 100 points requires about 300 second, for 1000 - it will be about 3000 seconds. It's too long for me.

How could I accelerate this process?

P.S.

Plotting of my function requires about 90 seconds for the entire range. So, this is very strange, thad converting to data list requres so much time.

Hi everybody,

Ever since i updated to maple 2015, the output of calculations display a disproportionate amount of zeros. For instance:

If i write:

2.3*10^(-4)

i get:

0.000230000000000

Is there anyway to make maple NOT display the last 10 zeros? I've tried Tools ->Options ->Precision -> Round screen display to X. But then it rounds all results to that X amount of digits, wich is also anoying. Like, if i set X to be 10, it'll write 3.000000000 instead of just 3.

Hope someone can help me :-)


Anton

the binomial coefficient  n k  can be defined recursively as follows for all nonnegative integers n, k:

(n)  = {0,      k>0

(k)  = {1       k=0, k=n

         {(n-1)+(n-1), otherwise.

          (k-1)   (k)

I need to complete a deinition of binom so that m so that binom(n,k) returns  n k  for all n greater than 0, and k greater than or equal to 0 using the definition of the binomial above..Any help appreciated..

binom:=
proc(n::TYPE1,k::TYPE2)
description "Compute a binomial coefficient";
option remember;
---MORE STUFF HERE---
end proc; # binom