MaplePrimes Questions

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

I try to find the exact (symbolic) value of

(-2*sqrt(7)-4)*EllipticK((1/8)*sqrt(2)*(-3+sqrt(7)))^2+4*EllipticE(-(1/8)*sqrt(2)*(-3+sqrt(7)))*sqrt(7)*EllipticK((1/8)*sqrt(2)*(-3+sqrt(7)))

I tried 'simplify' with different options and 'convert'. It would be pi=3.141... as numerical approximation suggests.

Many thanks.

I think Simpson's rule for integration is very simple and it is just function evaluation over a few points on the interval of integration. So we expect it to be fast.

When I use it as a summation command (using Simpson's formula) it is really fast but when I use the command ApproximateInt with Simpson method it is sometimes really slow. For example

restart;

f := unapply(x^2/(sin(x)+x+1), x);

with(Student[Calculus1]);

evalf(ApproximateInt(f(x), x = 1 .. 2, method = simpson, partition = 20));

or even with partition=10 you must wait for a long time.

Please help.

Thank you

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.

Maybe an easy question, but which command do I have to use to calculate the difference between e and a list of fractions?

App.mw

 

Hi all

 

I don't know why it doesn't work correctly? I want the final answer be in the form of De, U, UN not as beta1 and beta2

Please help me...

 

Hello Please, I was wondering if I can get this equation solve either in closed form or approximate form:

 

mu = theta*beta^a*(int(t^a*exp(-beta*t)/(-lambda*t+1), t = 0 .. infinity))/Gamma(a)

 

 

Many thanks 

Hello everyone,

 

I have a set of data that I have imported in Maple.  When I plot the data, I can see that there are two sine waves in it.  It is a plot of radial velocity of a star versus time.  This is about a reflex motion of a star with an orbiting planet.  We will set that there is only one planet.

I would like to extract those two sine waves.  I am including that *.csv file that I imported in Maple that you can download at this address.

https://www.dropbox.com/s/4f4j5xm565je30x/Tyr_rv9_Maple.csv?dl=0

This is not for an exam but it is for a course in February and this will be very helpful and I want to share this file.  I can predict that there will be more than one planet but it is the idea that is important.

 

Thank you in advance for your help.

 

--------------------------------------
Mario Lemelin
Maple 2015 Ubuntu 14.04 - 64 bits
Maple 2015 Win 10 Pro - 64 bits messagerie : mario.lemelin@cgocable.ca téléphone :  (819) 376-0987

Is there a way to permanent change the color of the output in maple?

Hi

My function is shown below:

restart;

f:=(x,y)->evalf[5](2*x*Int(sqrt(1+y^2*(t*x-1)^2/(1-(t*x-1)^2)), t = 0 .. 1)):

printf(" x     y     f(x,y)\n");    

for x from 0.1 to 1.9 by 0.1 do

for y from 0.1 to 0.9 by 0.1 do

printf("%g   %g   %g\n",x,y,f(x,y));

od; od;

 


I want a relationship as follows to be fitted values of x,y, f(x,y)

f(x,y)=a1*x*sqrt(1+y^2*((a2*x-a3)^2/(1-(a4*x-1)^2)))

a1,a2,a3,a4=Coefficients that must be determined

 

There are dozens of indefinite integral expressions in my worksheet. Everytime I execute the entire worksheet, the cursor always rests beside one indefinite integral expreesion and Maple stays in "Evaluating...". Even 30 minutes passed, the result of the integral couldn't come out. What bothers me is that the cursor would rest beside different indefinite integral expressions. For example, I write 4 indefinite integral expressions A, B, C and D one by one. First time, the results of A, B and C come out and the cursor rests beside D with "Evaluating...". Next time, the results of A and B come out and the cursor rests beside C with "Evaluating...".

Before the indefinite integral expressions, I wrote dozens of lines of codes aiming at assigning values to variables. As I typed more and more indefinite integral expressions into the worksheet, even evaluating the codes aiming at assigning values would spend more and more time.

Does Maple evaluate the codes line by line from the top to the end of a worksheet? If it is true, why evaluating the codes before the indefinite integral expressions becomes slowly?

How to evaluate the entire worksheet without stuck in one indefinite integral expression?

Hi everyone, this is my situation:

I've created a program inside a "Code editor region" within "Document mode" which I execute by pressing CTRL+E within the code editor region.

The program outputs an animation of the solution to the heat equation.

The thing is, the program contains some for-loops and I want to print some text in the end of each iteration within the for-loops so as to track the progress, e.g. I want to have printed        "The equations for time level k out of m were set up"

The problem is that in document mode you will get a huge amount of text added to your document which you'll have to delete, if you print about 1000 times.

So my question is:   Is it possible to use the "Command-line Maple 2015"-tool and/or modify the way I've set up my program such that the print statements are outputted to the terminal AND the animation pops up in a seperate window?

I've tried to run some simple commands in the maple-terminal such as:

        plot(x^2,x=-1..1);

but somehow the terminal displays it using regular text-symbols and stuff. I thought that it would just open up some seperate window, displaying a graph-plot as you would normally see in maple.

 

Hi. I want to solve this system of equations by varying the value of n. I managed to aolve and plot for n=1, 1.1 and 1.2 but it happens to be a problem when I let n=1.3.

>restart;

>Digits := 15;

>with(plots):n:=1.3: mu(eta):=(diff(U(eta),eta)^(2)+diff(V(eta),eta)^(2))^((n-1)/(2)):

>Eqn1 := 2*U(eta)+(1-n)*eta*(diff(U(eta), eta))/(n+1)+diff(W(eta), eta) = 0;

>Eqn2 := U(eta)^2-(V(eta)+1)^2+(W(eta)+(1-n)*eta*U(eta)/(n+1))*(diff(U(eta), eta))-mu(eta)*(diff(U(eta), eta, eta))-(diff(U(eta), eta))*(diff(mu(eta), eta)) = 0;

>Eqn3 := 2*U(eta)*(V(eta)+1)+(W(eta)+(1-n)*eta*U(eta)/(n+1))*(diff(V(eta), eta))-mu(eta)*(diff(V(eta), eta, eta))-(diff(V(eta), eta))*(diff(mu(eta), eta)) = 0;

>bcs1 := U(0) = 0, V(0) = 0, W(0) = 0;

>bcs2 := U(20) = 0, V(20) = -1;

>R1 := dsolve({Eqn1, Eqn2, Eqn3, bcs1, bcs2}, {U(eta), V(eta), W(eta)}, initmesh = 30000, output = listprocedure, numeric);


Error, (in dsolve/numeric/bvp) precision is insufficient for required absolute error, suggest increasing Digits to approximately 23 for this problem

>for l from 0 by 2 to 20 do R1(l) end do;
>plot1 := odeplot(R1, [eta, U(eta)], 0 .. 20, numpoints = 2000, color = red);


Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

 

I have tried increasing the Digits as suggested to 23, 25, 30, 31 up untill 500 yet still same error occur suggesting to increase the Digits. Is there any other way to solve this kind of error? Can someone help me? Thank you in advance.

 

Hi. I want to solve a system of equations. But I got this type of error. 

>restart;

>Digits := 15;
>with(plots):n:=0.7:Pr=1: mu(eta):=(diff(U(eta),eta)^(2)+diff(V(eta),eta)^(2))^((n-1)/(2)):
>Eqn1 := 2*U(eta)+(1-n)*eta*(diff(U(eta), eta))/(n+1)+diff(W(eta), eta) = 0:
>Eqn2 := U(eta)^2-(V(eta)+1)^2+(W(eta)+(1-n)*eta*U(eta)/(n+1))*(diff(U(eta), eta))-mu(eta)*(diff(U(eta), eta, eta))-(diff(U(eta), eta))*(diff(mu(eta), eta)) = 0:
>Eqn3 := 2*U(eta)*(V(eta)+1)+(W(eta)+(1-n)*eta*U(eta)/(n+1))*(diff(V(eta), eta))-mu(eta)*(diff(V(eta), eta, eta))-(diff(V(eta), eta))*(diff(mu(eta), eta)) = 0:
>Eqn4 := (W(eta)+(1-n)*eta*U(eta)/(n+1))*(diff(theta(eta), eta))-(mu(eta)*(diff(theta(eta), eta, eta))+(diff(mu(eta), eta))*(diff(theta(eta), eta)))/Pr = 0:
>bcs1 := U(0) = 0, V(0) = 0, W(0) = 0, theta(0) = 1:
>bcs2 := U(20) = 0, V(20) = -1, theta(20) = 0:
>R1 := dsolve({Eqn1, Eqn2, Eqn3, Eqn4, bcs1, bcs2}, {U(eta), V(eta), W(eta), theta(eta)}, initmesh = 20000, output = listprocedure, numeric);

Error, (in dsolve/numeric/bvp/convertsys) too few boundary conditions: expected 8, got 7

>for l from 0 by 2 to 20 do R1(l) end do;
>plot1 := odeplot(R1, [eta, theta(eta)], 0 .. 20, numpoints = 2000, color = red);

 

What is the problem actually because based on the paper that I refer to, there is only 7 bc. 

Can anyone help me?

Thankyou in advance.

Hello

Is there any option for impoting MATLAB's variables eith struct format (*.mat)?

Could you please to help me!

Thank you.

 

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