I got a problem with solving a second order ODE. 

The ODE is :

-V(xi)+(1/2)*xi*(diff(V(xi), xi))+(1/4)*(diff(V(xi), xi, xi))=-(1/2)*k2*(diff(H(xi), xi))-k1*n*X/E+1+k2

where k1,k2,n,X,E  all are constant.

the condition is :

V(xi) tends to 2*xi^2 as xi tends to infinity.

I used 'dsolve' to solve the equation firstly, and got a solution with two constant C1 and C2, I want to use the condition to elimilate C2, so I used limit(sol,xi=infinity)=2*xi^2. But when I used the command 'limit', I can't get the answer.

Could any one help me? 

Many thanks!!!

I am using Maple 18 on a Mac. I also uploaded the tetrad package.  I setup my metric but when I call Christoffel I get the following error.

Download Equation_2.16_using_DiffernetialGeometry.mw

I appreciate the help.

Hi,

I'm a newer of maple .I want to prove x=z,y=z from equations of parametric z.But maple don't solve what I want,who can give me a help .thank you

sometimes when I download something from Maple apps centers, such as this package, http://www.maplesoft.com/applications/view.aspx?SID=33406  I find the example documents there are written in .mw and when I open them, there are in document mode style, the fancy word like style which I can't stand looking at.  It has all the math input in italic and maple commands look different from classic Maple text. It very confusing, since I see something as   (0<x<1) which is valid in this document mode, but in classical maple, this is not valid code.

It seems Maple has 2 different syntax. One that works in document mode and one that is classical text maple.

I like to use only input as Maple notation which these documents do not do.

Is there a way to convert such .mw file to become standard classic worksheet mode? I know I will lose the chapter/section heading and all that.  I also tried selecting all in the document, then did Tools->options->Display->Input display->Maple notation, but nothing happend to the open document. It remained document mode with 2D math input.

When I save it as .mws, and open it again, it remains on document mode.

How to convert such documents to classical Maple syntax?

Short question version:

print(plots[display](seq(seq...   ...)):  works fine!  Why??

Longer, more detailed question:
  print(plots[display](seq(seq...   ...)):   This Maple statement ends in a colon - so I would not have expected any output.  I'm using "pretty" print, as opposed to printf, because it automatically centers the output

    This question is actually an extension of one I posed  yesterday, under the title "How to clear Maple output" - but the question I should have been asking is: "Why is the previous output not automatically cleared?"  The main points of that question are stated below.  Any comments, suggestions gratefully received.

   David

"How to clear Maple output"

I'd like to know how the screen previous ouput can be cleared.   ...or what is the likely cause.

   At the start of my program I have:

restart;
interface(echo=0, verboseproc=0, warnlevel=0, prettyprint=1):

#I thought restart; would automatically have cleared any previous output.

The program reads necessary input (eg no of players, ..)  using:

x:=readline(terminal):

I would like to look at a 3d plot including an condition about the two variables of the plot

For this simple case, I only want to see the plot with the condition that x>0. Is that possible?

plot3d(x*y,[x,0,1],[y,0,1]);

Hi all,

which alternative options fo I have to prove the equality of two algebraic expressions if testeq fails?

The case im reffering to can be seen in the following document:

https://dl.dropboxusercontent.com/u/29147149/Exam%202006%20Question%20A.mw

Equation 14-18

I am pretty sure that the expressions are equal. evalb just returns false because it does not simplify expressions.

howdy.

evalf(map(log10,[25,5,1,10,4,20]))=

[1.39794000867203, .698970004336017, 0., 1., .602059991327960, 1.30102999566398]

How do I reverse this process , ie get back [25,5,1,10,4,20] using map command. Obviously it's 10 to the power but map(10^,[1.39794000867203, .698970004336017, 0., 1., .602059991327960, 1.30102999566398]) won't work

I'd like to plot the following inequalities:

sqrt(x)<=1/sqrt(2)

1/sqrt(2)<sqrt(x)<=1/sqrt(2)

Hey!

I have this MATLAB script, but as I work in Maple, I'll need to translate it to Maple. 
I know how to define symbols and functions, but I don't know which Maple commands to use, of if it needs to be done in another way, so the problem is translating from " dZ = [dx; dy; ax; ay; dm];" and down.

Any help would truly be greatly appreciated! Thank you!  

This is the script:

function dZ = meteor_step(~, Z)

  P = 1.2; % initial atmospheric pressure
  H = 1.39E-4; % scale height of atm pressure
  E = 8.11131859E6; % evaporation energy
  D = 1; % drag constant
  G = 9.814; % acceleration due to gravity
  PM = 3.3E3; % density of the meteor
  
  S = 3.986E14; % standard gravitational parameter of Earth (G*M)
  R = 6.3674447E6; % radius of the Earth (meters)

  x = Z(1);  
  y = Z(2);
  dx = Z(3);
  dy = Z(4);
  m = Z(5);
  
  atm = P*exp(-y*H);

  v = sqrt(dx^2+dy^2);

  area = pi * ( (3*m)/(4*PM) )^(2/3);

  dist = sqrt(x^2+y^2);
  Gv = -9.8;

  accel = -(D*atm*area)/m*v;
  ax = accel * dx;
  ay = accel * dy + Gv;
  

  dm = -(atm*v^3*area)/(2*E);
  
  dZ = [dx; dy; ax; ay; dm];
  
end

[t, R] = ode45(@meteor_step, [0 250], [0, 100000, 100, -300, 25]);

x = R(:,1);
y = R(:,2);

dx = R(:,3);
dy = R(:,4);

v = (dx.^2+dy.^2).^(1/2);

m = R(:,5);

figure(1);
plot(t, y);
  title('Meteor Kinematics: Height vs Time');
  xlabel('Time elapsed (s)');
  ylabel('Height (m)');

figure(2);
plot(x, y);
  title('Meteor Kinematics: Horizontal vs Vertical Position');
  xlabel('Horizontal (m)');
  ylabel('Vertical (m)');

figure(3);
plot(t, v);
  title('Meteor Kinematics: Speed vs Time');
  xlabel('Time elapsed (s)');
  ylabel('Absolute speed (m/s)');

figure(4);
plot(t, m);
  title('Meteor Kinematics: Mass vs Time');
  xlabel('Time elapsed (s)');
  ylabel('Mass (kg)');

  
figure(5);
plot(t, dy);
  title('Vertical Velocity vs Time');
  xlabel('Time elapsed (s)');
  ylabel('Vertical velocity (m/s)');

temp = abs(y - 52900);
[~, index] = min(temp);
  
t(index)
dx(index)/1000
dy(index)/1000

I've got a worksheet in which I have invested many hours of CPU execution time and if the computer goes down, or Maple fails for some reason, I'll lose it all.

If this happens I would like to be able to continue the calculation from where I left off.

By saving the worksheet periodically, I can save all the commands, but not the results, so if I have to restart, I'll have to wait many hours before the worksheet catches up to where it left off.

In ancient versions of Maple, you used to be able to save an executed worksheet including results (I sort of remember that you wrote a file with the extension ".M")  but the new help pages say that is now different from what it used to be. Obviously I can "save" individual symbols to a file, but for a complicated worksheet  that gets complicated.

I've read about "maplet" files, but that doesn't seem to fill the bill either.

So, is there any simple way to save a worksheet so you can continue seamlessly from where you left off after a crash, with all the previous results intact?

I have written a program which plays the game of Multicube, a commercially made boardgame. It works OK except that when the game is replayed, the previous game output stays on the screen.  This is rather distracting and I'd like the screen cleared when a new game is run.   I'd like to know how the screen previous ouput can be cleared.   ...or what is the likely cause.

   At the start of my program I have:

restart;
interface(echo=0, verboseproc=0, warnlevel=0, prettyprint=1):

#I thought restart; would automatically have cleared any previous output.

The program reads necessary input (eg no of players, ..)  using:

x:=readline(terminal):

Thanks,  David

Was trying to see if I can get the reduction formulas for int(cos(x)^n,x) in maple. But it seems no assumption used can make Maple give any result for this.  Mathematica gives a result using Hypergeometric2F1 (even with no assumption on n, which I am not sure about now), but was wondering why maple can't do this one:

restart;
int( (cos(x))^n,x) assuming n::integer;

                     
int( (cos(x))^n,x) assuming n::posint;
                        same

In Mathematica, I get:

I am newbie in Maple, so may be I am missing some command or doing something wrong.

ps. I was trying to obtain

But this is lost case now. I just need to find out first why int(cos(x)^n,x) does not evaluate to anything in Maple.

fyi, the Hypergeometric result for $\int cos^n(x) \,dx$ can be seen in this reference (half way down the page):

http://www.integraltec.com/math/math.php?f=cosPower.html#cos

ps. can't one enter Latex in this forum like at stack exchange?

Hello,

I am trying to solve the boundary value problem (1-x^2)*y'' - 2*x*y' +12*y = 0 with y(-1) = -1 and y(1) = 1.  I have not used Maple much, but from some web surfing, it seems like the following inputs should work:

de := (1-x^2)*(diff(y(x), `$`(x, 2)))-2*x*(diff(y(x), x))+12*y(x) = 0

Y := dsolve(de, y(-1) = -1, y(1) = 1)

However, when I input these lines, I get the error: Error(in dsolve), found wrong extra argument(s): y(-1) = -1, y(1) = 1

Does this mean that Maple can't solve this problem?  Is my syntax wrong?  I would appreciate any help.

Thanks!

Tim

What are the stopping criteria for fsolve?
I cannot find anything in the help page and there seems to be no way of adding an optional argument to fsolve about errors.

I was initially surprised by the results of the first two fsolve commands below:

restart;
infolevel[fsolve]:=2:
fsolve([x->1,x->3],[0.4,8]);
fsolve([x->1,x->3],[0..7,8..9]);
fsolve(x->1,0.4); #OK, returns unevaluated
fsolve([1,1],{x,y}); #OK, returns NULL

I assume that in the first two examples the criterion used is that at some point in the process the iterates [x(n+1),y(n+1)] and [x(n),y(n)] are close enough together and the difference between results from the two is small enough (clearly 0).