Hi all.

After installation of the MSK, there is no desktop icon, and there is nothing to click in the start menu to launch it. I have to click on the executable in the Maple folder on the hard drive. It then launches Maple 18 first, and opens up some tabs related to the Survival Kit.

How can I open the MSK up from within Maple, without having to search for the executable first on the hard drive? 

Thanks in advance.

Hi all

I am trying to maximize a function f(x,y,z,w) in terms of x. (Only x is treated as a variable, and the others are treated as parameters).

However, all I know is that y,z,w they are parameters and they are non-negative. I have already tried with the "optmization help page" from maplesoft's website, and it looks like it will search the range of x,y,z,w, and it will return numerical values at which this function is maximized. 

However, what I want is instead a close-form solution of x=g(y,z,w) that will maximize the function.   In other words, I would like to keep the parameter in symbolic forms. 

Can Maple do that?

restart;
k:=1;
sum(k^2,k=1..10);
      (in sum) summation variable previously assigned, second argument

gives an error, since k is not free. Fine. No problem. But add() has no problem with an assigned variable:

restart;
k:=1;
add(k^2,k=1..10);

and seq() has no problem either

restart;
k:=1;
seq(k^2,k=1..10);

It is confusing when learning Maple since it does not seem to behave the same way in all its functions. What is the reason for this design? 

I have 3 column vectors:

phi contains the number of radians from the North Pole

theta contains the number of radians from the Greenwich meridian

D contains number data corresponding to the point (phi,theta) on the sphere.

How do I plot:

a) a contour plot on the surface of the sphere where each point at (phi, theta) has a corresponding data value D?

b) a plot where the height above the surface at (phi, theta) is some linear function of D such as radius*D*constant?

Hi,

On page 32 （PDF）

Two different results were obtained using the Global optimization.

Log likelihood does not differ much. BUT the estimates vary a lot, such as mu[p].

tmp.mw

tmp.pdf

When I tried to use one of the answer from a particular run, I get the HFLOATING error, see picture.

So how reliable is this? Could there be a better way to optimize this ?

Thanks!

As an additional note, if I have Matlab R2014a, could I use Matlab to optimize the target function? DO I need to purchase a seperate addon?

I have a Matrix of data points I am plotting using plots:-listdensityplot. That works fine.

However, the axes are labeled by row and column number of the Matrix (e.g. 1..20 or whatever). In reality, these are of course some parameters the range of which has been mapped onto the rows and columns of the Matrix.

How can I display the axes using the values of the original parameters? I know the transformation from Matrix row or column to the actual parameters (and in this case it is linear).

TIA,

Mac Dude

Hi experts,

the standard resolution for maple contourplots is 72 dpi wich is not suitable for publication purposes. I need at least a resolution between 500 - 1000 dpi. How do I get better resolutions for my contourplots when exporting them to .bmp or .jpg-files?
Somebody any ideas?

Consider the differential equation   d/dx y(x)=2*y(x)*(y(x)-4), on the rectangle -1 < x < 1, -2 < y < 7.40 in the xy-plane.

(a) Use DEplot to plot the direction field for the differential equation on the given domain. Assign your answer to my_plot_1.

restart: with(DEtools):
DEexp1:=2*y(x)*(y(x)-4);

DE:=Diff(y(x),x)=DEexp1;

DEplot(DE, y(x), x=-1..1, y=-2..7.4);
Error, (in DEtools/DEplot/CheckDE) derivatives must be given explicitly

Thanks for your help!

Level: Idiot (Me)

I have a matrix of 3 columns and lots of rows M

• First column is latitude in degrees
• Second column is longitude in degrees
• Third column is data

So I set lambda:=M(..,1) and phi_g:=M(..,2) giving me two column vectors.

I want to convert lambda and phi_g to polar coordinates theta and phi

theta:=90-lambda produces "Error, (in rtable/Sum) invalid arguments"

WHY?

I also want to convert phi_g to phi where phi=phi_g when phi_g is 0...180 and phi=phi_g +360 when phi_g <0

How do I create a conditional function like this?

How can I get the Automorphism Group of a group G as a Permutationgroup?

Best regards

Kurt Ewald

Hello,

this is the second time I'm writing.

I posted this question in June http://www.mapleprimes.com/questions/201781-System-Of-Parametric-Equations.

This time I have  a similar problem because I'm trying to find a solution for a parametric system of equations but the number of equations and parameters is much bigger and using the tips you gave me last time I couldn't reach any result.

Here is the system:

1) alpha[1]=v*a*u*b ;
2) alpha[2]=v*a*u*(1-b);
3) alpha[3]= v*z*c*(1-a) ;
4) alpha[4]=v*z*(1-a)*(1-c) ;
5) alpha[11]=1/2*v*a* u* b* (-p*u*b+p*u*b*a+b*g-g);
6) alpha[22]=1/2*v*a*u*(1-b)* (p u b-p u b a-b g-p u+p u a);
7) alpha[33] =1/2*v*c*z*(1-a)* (c* (-z*p*a+q)-q);
8) alpha[44]=1/2*v*z*((1-a)*(1-c)* (c*z*p*a-z*p*a-q*c);
9) alpha[12]=v*a*u*b*(1- b)*(-p*u+p*u*a+g) ;
10) alpha[13]=v*a*u*b*z*c*p*(1-a) ;
11) alpha[14]=a*u*b*z*(1-a)*(1-c) ;
12) alpha[23]=a*u*z*c*(1-a)*(1-b);
13) alpha[24]=v*a*u*z*p*(1-a)*(1-b)*(1-c);
14) alpha[34]= v*c*z*(1-a)*(1-c)*(-z*p*a+q);

I have 14 equations/unknowns and 8 parameters (a, b, c, u, v, z, p, q).

I would like to write this system only in terms of alphas. In order to do so, I usually try to find the value for the parameters and the substitute them into the equations (and I have already found b,c,g,q using this technique) but I couldn't manage to find all of them. 

Howveer, as you suggested me, with Maple there is the command "eliminate" that implement exactly what I'm looking for but I can't make it work.

This is my code:

> sys := {alpha[1] = v*a*u*(1-b), alpha[2] = v*a*u*b, alpha[3] = v*z*c*(1-a), alpha[4] = v*z*(1-a)*(1-c), alpha[11] = (1/2)*v*a*u*(1-b)*(p*u*b-p*u*b*a-b*g-p*u+p*u*a), alpha[12] = v*a*u*b*(1-b)*(-p*u+p*u*a+g), alpha[13] =      z*c*a*u*(1-a)*(1-b), alpha[14] = v*z*a*u*p*(1-a)*(1-b)*(1-c), alpha[22] = (1/2)*v*a*u*b*(-p*u*b+p*u*b*a+b*g-g), alpha[23] = v*z*c*a*u*b*p*(1-a), alpha[24] = z*a*u*b*(1-a)*(1-c), alpha[33] = (1/2)*v*c*z*(1-a)*(c*(-z*p*a+q)-q), alpha[34] = v*c*z*(1-a)*(1-c)*(-z*p*a+q), alpha[44] = (1/2)*v*z*(1-a)*(1-c)*(c*z*p*a-z*p*a-q*c)};

> eliminate(sys, {a,b,c, p, q, u, v, z});

> simplify(%, size);

I also tries to substitute in the system the four parameters I already found but still I can't find a solution.

What am I doing wrong? Or the problem is that it is too complicated?

Thank you for your attention,

Elena

Hi

I can't solve the problem to have the right solution of

solve({cos(x)!=0,x>=0,x<=2*Pi})

while solve works with

solve(cos(x)!=0)

Any ideas on why this happen?

restart:
Eq1:=r^2*diff(w(r),r$2)+r*diff(w(r),r$1)-r^2*G5*w(r)-P*r^3*G6-G7*r^3-G8*r^5+C1*r/G3=0;

res1:=dsolve(Eq1);

bcs:=D(w)(0)=0,w(h)=0;

res2:=(dsolve({Eq1,bcs},w(r)));

match(rhs(res2)=rhs(res1),r,s);

eval(_C2, s);

Any idea?

Thanks

We know that sum can return an symbolic summation, for example,

But sometime the relation of parameters in series cannot be defined easily. And it seems that sum cannot correctly determine the symbolic summation of this kind of series:

Maybe it's due to the value of _C(infinite) is undefined. Does anyone have good idea to compute the symbolic summation of this series?

I'd appreciate any help on this topic. Thank a lot.

sum_cannot_return_symbolic_summation.mw

Dear all,

I tried to display an animation which can zoom as the time goes.

But it seems that if I display several animations in one plot window, it will display the animation with the maximum view size from these animations, not separately display these animations with their view size.

There are two examples:

Case1,

a1 := animate(plot, [x^2, x = -1 .. t, view = [-1 .. 1, 0 .. 1]], t = -1 .. 1);

a2 := animate(plot, [x, x = -1 .. t, view = [-1 .. 1, -1 .. 1]], t = -1 .. 1);

display(a1, a2);

Case2,

animate(plot, [x^2, x = -1 .. 1, view = [t .. 1, 0 .. 1]], t = 0 .. -1)

Is it possible to zoom the animation with time? What parameter should I set?

The related maple file is attached.

zoom_animation_with_time.mw