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).

I have the following situation:

HB:=Bend(L,a,n);

Bend is a proc, that returns a Record with info based on its parameters. I would like to get access to the name I assign to (i.e. HB) in the proc. Any chance?

Mac Dude

PS: I can of course kludge things by adding an argument to the proc Bend. But I'd like to avoid that.

Good day,

I am working under paper which contains comparison of different tensor software packages focusing on the algebraic manipulations with tensors (namely Maple Physics, Mathematica xAct, Cadabra and Redberry). When doing comparison we’ve found that Maple Physics `Simplify` function sometimes fails to perform even trivial simplifications and almost does not work on harder examples. For example, one can easily see that all expressions below are zero while Maple Physics is unable to simplify them:

with(Physics):with(Library):Setup(spacetimeindices = lowercaselatin):

Define(A[a]):Define(B[a,b]):Define(F[a,b,c]):Define(H[a,b,c,d]):Define(J[a,b,c,d,e]):

#Does not give zero:

Simplify(J[~g,g,f,a,~f]-J[~f,f,g,a,~g]);

#Does not give zero:

Simplify(J[~f,a,b,g,c]*F[~e,f,~d]*F[e,d,~g]-J[~e,a,b,f,c]*F[~d,e,~g]*F[d,g,~f]);

#Does not give zero:

Simplify(A[c]*J[e,~h,h,i,b]*J[~d,~i,d,a,~e]-A[c]*J[d,~h,h,e,b]*J[~i,~e,i,a,~d]);

#Does not give zero:

Simplify(H[~e,b,~f,d]*J[f,c,a,~d,e]-H[~f,b,~d,e]*J[d,c,a,~e,f]);

#Does not give zero:

Simplify(F[d,~e,e]*F[~d,~f,f]-F[~e,~d,d]*F[e,~f,f]);

#Does not give zero:

Simplify(J[g,c,k,~j,~e]*H[i,h,a,~h]*H[e,b,~i,~g]*F[d,~k,j]-H[h,b,~g,~j]*F[d,~k,e]*J[j,c,k,~e,~h]*H[g,i,a,~i]);

#Does not give zero:

Simplify(B[~e,~c]*H[~f,g,c,e]*B[a,~d]*H[~g,b,f,d]-H[~f,b,g,e]*B[~d,~c]*B[a,~e]*H[~g,f,c,d]);

#Does not give zero:

Simplify(A[~c]*H[d,h,c,b]*F[~h,~d,f]*H[a,e,~e,~f]-A[~h]*H[a,c,~c,~f]*F[~e,~d,f]*H[d,e,h,b]);

I’ve attached a single Maple file with about 250 such examples (Maple18_failSimple.txt) and a file (Maple18_allSimple.txt) with 1000 simple examples I used: some of them work correctly, while some fails. All these examples perfectly work in other systems (Mathematica xAct, Cadabra and Redberry).

We use Maple18 with latests Physics package version (December 12), but we also tried latest Maple17 and other versions of Physics: none of them work. In all these examples all tensors have no symmetries, but we observe even worse results in case when tensors have symmetries (nearly all tests fail).

What is important is that when we try to test a little bit more complicated examples, which can be simplified by other packages within milliseconds, Maple Physics not able to perform basic simplification in nearly all cases. I have attached a file (Maple18_failMedium.txt with failed examples and Maple18_allMedium.txt with all examples we used) with more complicated but still simple examples (one can check each example by hand): Physics not able to simplify more than 50% of examples. Finally, I’ve attached harder examples which perfectly work in all three other systems, but none of them work in Maple Physics (Maple18_allHarder.txt).  

So, my question is why `Simplify` is not able to perform such basic simplification of tensorial expressions? May be I miss something and I need to use another special command?

If we are using `Simplify` in a right way, Maple Physics can not be considered as a package for tensorial algebra (in the opposite to what is declared on the Maple website) until these basic simplification functionality will work.

PS

For generating input expressions we’ve written a little program that allows to generate random typical tensorial expressions arising in real computations (like calculation of Feynman diagrams etc.) and to run different system on such expressions in order to simplify them. Specifically we generate an expression (nested sums/products of tensors), then rewrite it in equivalent form (by renaming dummies, shuffling summands and multipliers and expand) and then subtract the result from initial expression. Obviously, simplification of such a prepared source must give zero.  

Maple18_failSimple.txt

Maple18_allSimple.txt

Maple18_failMedium.txt

Maple18_allMedium.txt

Maple18_allHarder.txt

Edit: Here are some trivial examples that the latest fixed version (version 41.1 Dec/15) still fails to resolve correctly (besides Maple18_allHarder.txt that are still not working in the fixed version):

with(Physics): with(Library): Setup(spacetimeindices = lowercaselatin):

Define(A[a]):

Define(B[a,b], antisymmetric={{a,b}}):

Define(H[a,b,c,d], antisymmetric={{a,b,c,d}}):

#Does not give zero

Simplify(A[c]*B[d,~e]*B[~d,f]*H[e,~f,b,a], tryhard);

Without symmetries:

with(Physics):with(Library):Setup(spacetimeindices = lowercaselatin):

Define(A[a]):Define(B[a,b]):Define(F[a,b,c]):Define(H[a,b,c,d]):Define(L[a,b,c,d,e,f,g]):

#Does not give zero

Simplify(F[~f,~h,j]*L[~k,~i,h,k,~j,c,m]*H[e,b,a,~d]*H[d,~l,i,~e]*F[~m,f,l]-H[f,b,a,~k]*H[k,~l,j,~f]*F[~i,m,l]*L[~e,~j,d,e,~h,c,i]*F[~m,~d,h],tryhard);

etc.

Another important issue is that with the current fixed version, the time used by `Simplify` became unacceptably large. As in the notebook that ecterrab provided, Maple Physics takes about 20 minutes on 100 medium examples (Download Simplified100MediumExamples.mw), while other packages spend just few seconds.

We are looking forward for the future updates that will solve these issues.

Hi,

I'm trying to solve the following differential equation numerically with dsolve:

but dsolve gives me this error:

> res := dsolve(DGL, numeric, parameters = [y0, A, B, C, E]);
Error, (in DEtools/convertsys) unable to convert to an explicit first-order system

I think the problem is that I use the wrong solver. Does Maple provide a solver which is capable of solving this kind of equations (nonlinear ODE)?

Thanks in advance!