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Hello

I have a loop with the do structure but there is an error in the loop .

how can I continue the loop by error or disregard it?

Hello,

 

could you help me solve this error ? I don't understand what it means.

 


> eq3:=diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*(x(t)-(diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*x(t)+omega[0]^2*X[0])/omega[0]^2) = -omega[0]^2*X[0]:
> dsolve(eq3);
Warning, it is required that the numerator of the given ODE depends on the highest derivative. Returning NULL.

 

Thanks.

I have a great problem with this integral and Maple gives two answers completely different:

 

int(x^-5/3*cos((x-1)*h), x = 0..infinity)

so I get two different results :

 

-(27/8)*h^2+3/2+(27/8)*h^(7/6)*LommelS2(11/6, 1/2, h)

 

or this:

 

-(27/8)*h^2+3/2+(27/8)*h^(7/6)*LommelS1(11/6, 1/2, h)

In the first integral A get Lommels2 and If I get the Integral by using Taylor of cos((x-1)*h) and after that I resum I get Lommels1.

 

Thank you.

 

 

 

Greetings everyone. I tried to get the roots of this polynomial by using allvalues command. But I got the roots in indeces instead of the value of the roots.

what should i do?

Hello! I wrote a program in Maple but it doesn't work. It crashes with the following error: "Error, (in r_nach_1[3]) too many levels of recursion". I am a newbie in Maple and don't know how to solve this problem. A part of my program that causes the error is given below. Many thanks!

maple.mws


restart;
t1F := 20: A11 := 2.5*10^(-3): c1 := 4*10^2: ss1 := 0.5*10^(-2):
pI1 := 0.4*10^(-1): r1max := 0.6*10^(-2): procent:=0.2:
A12 := procent*A11: B1:=-1: alpha:=0.000001:

beta1:=0.5: r_nach_1[1]:=0: r_nach_1[2]:=0.2*10^(-2):


iter_psi_c1_1:=proc(t) 0 end proc: iter_psi_c2_1:=proc(t) 0 end proc:
s1[1]:=proc(t) 0 end proc:



for i from 1 to 2 do

_p11 := evalf(dsolve({
diff(p1(t), t) = A11*(p1(t)-'s1'[i](t))+B1*(r_nach_1[i+1](t)-r_nach_1[i](t))+A12*(p1(t)-'s1'[i](t))^2+ss1,
p1(0) = pI1}, numeric,method = dverk78, abserr = 1.*10^(-8), relerr = 1.*10^(-8),optimize,output = listprocedure, known=[s1[i],iter_psi_c1_1,iter_psi_c2_1])):

p1F := rhs(_p11(t1F)[2]):
s1[i+1] := subs(_p11, p1(t)):

q11 := evalf(dsolve({diff(q1(t), t) = c1*r_nach_1[i+1](t), q1(0) = 0},numeric,range=0..t1F,known=[iter_psi_c1_1,iter_psi_c2_1])):

q1F := rhs(q11(t1F)[2]):


F[i]:= beta1*q1F;

_psi_c1_1 :=
evalf(dsolve({
diff(psi_c1_1(t), t) = A11+2*A12*('s1'[i+1](t)-'s1'[i](t))*psi_c1_1(t), psi_c1_1(t1F) =  -1+beta1},numeric,method = dverk78, abserr = 1.*10^(-8), relerr = 1.*10^(-8),optimize,known=[s1[i],s1[i+1]],output=listprocedure)):

_psi_c2_1 :=evalf(dsolve({
diff(psi_c2_1(t), t) = 0, psi_c2_1(t1F) =  -beta1},numeric,output=listprocedure)):
iter_psi_c1_1 := op([2,2],_psi_c1_1):
iter_psi_c2_1 := op([2,2],_psi_c2_1):

r_nach_1[i+2] := t-> r_nach_1[i+1](t) +  alpha*(B1*(iter_psi_c1_1(t)) + (c1*iter_psi_c2_1(t))):

_p11 := evalf(dsolve({
diff(p1(t), t) = A11*(p1(t)-'s1'[i+1](t))+B1*(r_nach_1[i+2](t)-r_nach_1[i+1](t))+A12*(p1(t)-'s1'[i+1](t))^2+ss1,
p1(0) = pI1}, numeric,method = dverk78, abserr = 1.*10^(-8), relerr = 1.*10^(-8),optimize, output = listprocedure, known=[s1[i+1],iter_psi_c1_1,iter_psi_c2_1])):

p1F := rhs(_p11(t1F)[2]):

s1[i+2] := subs(_p11, p1(t)):

q11 := evalf(dsolve({diff(q1(t), t) = c1*r_nach_1[i+2](t), q1(0) = 0},numeric,range=0..t1F,known=[iter_psi_c1_1,iter_psi_c2_1])):

q1F := rhs(q11(t1F)[2]):

F[i+1]:= beta1*q1F;


od:
Error, (in r_nach_1[3]) too many levels of recursion

1. nonlinear ODE with parameter "epsilon"

(x^n +epsilon*y(x))dy/dx + n*x^(n-1) * y(x) =m*x^(m-1) ; y(1)=b>1

where n=2,3,4,.. and m=0,1,2,3,...

 

2. Duffing equation with parameter "epsilon"

d^2 y(x)/dx^2 + y(x) + epsilon*y(x)^3=0 ; y(0)=A ; y'(0)=0

Hi, im new with maple

so I am still a bit confused with how to use it..

i have an nonlinear ODE with parameter "b"

(x+b*y(x))dy/dx + y(x) =0 ; y(1)=1

if i want b=0.1 and x=0, 0.1, 0.2, ..,1

how do i

Useing the following procedure I'd like to collect a set of  roots in a list of lists, so they can be manipulated and presented in various plot options. Some of which could be very interesting (to me only perhaps).

One option is to create a loop which produces values of newton roots x0 for a given function. For example:              f:=x->(x^7)-5

for x from -1 to 1 by 0.05 do

To highlight the problem I am haveing let us observe the following example. If we solve the following numerically,

d2/dx2 (s(x)) +s(x) -1=0,

ic: s(0)=1/2,s'(0)=0

How would I go about createing a plot of (s(x),x) for  x a member of [0,2*Pi) (useing polar coordinates clearly)?

The probelm I am haveing is plotting for x a member of [0,2*Pi). I know how to do this for x a member of [0,2*Pi] and (0,2*PI), but not  [0,2*Pi).

Hi i have difficulty to obtain the function of theta(eta) and diff(theta,eta) form the matrix. Every time i have to take the values from the matrix inorder to make the function of theta(eta) and diff(theta(eta),eta) which is very difficult.

Can you please make a code in MAPLE so that i may get the direct fuction of theta(eta) and diff(theta(eta),eta)from the matrix gernerated by MAPLE.

i WILL WAIT FOR YOUR QUICK RESPONSE.

Hi

I am a PhD scholar at the University of Queensland. I am reviweing a paper titled as "A similarity solution for laminar thermal boundary layer over a flat plate with a convective surface boundary condition"(the pdf is available online). In this paper the author has written a MAPLE code. I copied the same code in MAPLE but could nt succedded. The author used the Runge Kutta RK5 Method to solve the model.

Please help me to solve the same model...

I try to write sqrt(4) so that it will not be calculated to 2. I typed uneval(sqrt(4)) and received sqrt('4'). I do not want quotes surrounded number 4. How can I suppress it? Is there another way to write sqrt(4) without calculation to 2?

I want to be able to create expressions in the two noncommutative variables a and b such that an expression

(b+a)*a +ba symplifies to a*a. Thus the first expression expands to ba+aa, which when added to ba

yields ba+aa+ba=aa.

How to arrange for this will be greatly appreciated.

I want to solve numerically the nonlinear problem 

a*(diff(y(x), x, x))+2*(diff(y(x), x))+exp(y(x)) = 0, y(0) = 0, y(1) = 0

by defining my own method defined as 

yn+1=yn+2*h*(-2*yn+2*ln(2/(1+x))-(1/2)*a)^2/(a*(-4*yn+4*ln(2/(1+x))-a-h*(4*yn-4*ln(2/(1+x))+a+x+1)/a))

where h is the step-size. Please help me by letting me know how can I do this using Maple 11.

 

I'm working on a project that involves solving a large system of polynomial equations using 'solve', with some inequalities of the form "a<>b" or "a<>0". Initially, I was using Maple 9.5 with great success; the machine I was using was upgraded to Maple 11, and now 'solve' struggles with problems that were previously easy (<30 seconds).

Were there any major changes in 'solve' between these two versions? (No, according to the documentation; Yes, according to the source....

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