Hi,

I want to display several plots insequence and tried creating a list of polygonplot3d objects called "plotlist" and using them as an argument like this:

display(plotlist)

which triggered the error message:

Error, (in plots:-display) expecting plot structure but received: plotlist

Where's my mistake and how could I achieve the desired outcome? (displaying polygon3dplots in sequence)

Best Regards

Good day everyone,

Please I do get numerical output/values in this solution U1.mw

Best regards

please help me a bout:

> u := am+bm*m0*x(t)+cm*n0*y(t);
> v := an+bn*m0*x(t)+cn*n0*y(t);
> eq1 := diff(x(t), t) = 2*A*(sinh(u)-x(t)*cosh(u));
> eq2 := diff(y(t), t) = 2*A*(sinh(v)-y(t)*cosh(v));
> init := x(0) = X, y(0) = Y;
> sol := dsolve({eq1, eq2, init}, {x(t), y(t)});
> param := A = 1/2, am = 0, bm = 1.2*exp(-4), cm = .5*exp(-5), m0 = 10000, an = 0, bn = -exp(-4), cn = 1.2*exp(-3), n0 = 1000;
> ;
> save u, v, param, " narm.sav";
Warning, unassigned variable `u` in save statement
Warning, unassigned variable `v` in save statement
Warning, unassigned variable `param` in save statement
> init := x(0) = 0, y(0) = 0.1e-1;
> eq1 := subs(param, eq1);
> eq2 := subs(param, eq2);
> sol := dsolve({eq1, eq2, init}, {x(t), y(t)}, numeric);
> with(plots);
> odeplot(sol, [x(t), y(t)], 0 .. 60, numpoints = 300, view = [-1 .. 1, -1 .. 1]);

How do I control colors in such Maple program using plot3d? Is it possible to define the conditions?

> restart: with(plots):
      mandelbrot := proc(x, y)
     local c, z, m;
     c := evalf(x+y*I);
     z := c;
     for m from 0 to 30 while abs(z) < 2 do
        z := z^2+c
        od;
        m
     end:
 >    plot3d(0, -2 .. 0.7, -1.2 .. 1.2, orientation=[-90,0], grid=[40, 40], 
       style=point, scaling=constrained, color=mandelbrot);

I have a (251*1) vector for which I need to compute the cumulative sum. I'm currently using :

s:=Statistics[CumulativeSum](prices[1..251,1])

defined under the Statistics package but this method doesn't return an output, even though the argument passed is a vector.

Is there another method I can use?

dx/dt=2x(1-x/2)-xy, 

dy/dt=y(9/4 -y^2)-(x^2)y 

hi. please help me about modeling population migration. i am writing a sample for drawing plot in maple, however maple has not any error, but working incorrectly. my program is:

> u := am+bm*m0*x*t+cm*n0*y*t;
> v := an+bn*m0*x*t+cn*n0*y*t;
> eq1 := diff*(x*t, t) = 2*A*(sinh(u)-x*t*cosh(u));
> eq2 := diff*(y*t, t) = 2*A*(sinh(v)-y*t*cosh(v));
> init := x*0 = X, y*0 = Y;
> sol := dsolve*({eq1, eq2, init}, {x(t), y(t)}, numeric);
> param :=A=1/(2) ,am=0 , bm=1.2*(e)^(-4) ,cm= 0.5*(e)^(-5) ,;
> m0 = 10000, an = 0, bn = -exp(-4), cn = 1.2*exp(-3), n0 = 1000;
> save u, v, param, " narm.sav";
> init := x*0 = 0, y*0 = 0.1e-1;
> eq1 := subs*(param, eq1);
> eq2 := subs*(param, eq2);
> sol := dsolve*({eq1, eq2, init}, {x(t), y(t)}, numeric);
> with*plots;
> odeplot*(sol, [x*t, y*t], 0 .. 60, numpoints = 300, view = [-1 .. 1, -1 .. 1]);
> odeplot*(sol*d, [t, x*t, y*t], 0 .. 60, numpoints = 300, orientation = [70, 55], colour = black, axes = normal);
> init := x*0 = -1, y*0 = 1;
> sold := dsolve*({eq1, eq2, init}, {x(t), y(t)}, numeric);
> odeplot*(sold, [x*t, y*t], 0 .. 60, numpoints = 300, view = [-1 .. 1, -1 .. 1], color = black);

I've got an excel file and a maple file saved in the same folder and am trying to import the contents of the excel file using  the Exceltools[Import]("name of file.extension") command as given in the manual but it doesn't seem to work. I've also tried copying the entire path of the file in the argument but that doesn't seem to work either. What am I doing incorrectly?

Is it possible to use an option similar to range when using lsode method for dsolve? The ODEs I am trying to solve is stiff and will not work with the flag stiff=true or with method=rosenbrock unless i set Digits:=20. I want to avoid doing that as much as possible, since I believe wit will be very taxing, computationally. I have a very large systeom to solve. I found that method=lsode works with the default Digits=15. 

However I need to have the solutions in a given range stored for future access and manipulations. Using range gives me an error: 

Error, (in dsolve/numeric/an_args/lsode) lsode keyword was range, optional keyword must be one of 'ctrl', 'initial', 'itask', 'output', 'procedure', 'procvars', 'start', 'number', 'abserr', 'relerr', 'maxfun', 'minstep', 'maxstep', 'initstep', 'startinit', 'implicit', 'optimize', 'complex'

I cannot figure out how to use range or something similar with lsode. Anyone knows? 

Hello,

I am solving a large system of ODEs, using the following command,

> Sol := dsolve({seq(ode[j], j = 0 .. 21), seq(v[j](0) = 0, j = 1 .. 21), v[0](0) = 1}, [seq(v[j](t), j = 0 .. 21)]);

>

and then plot the quantities I want by something like

> plots:-odeplot(Sol, [t, v[3](t)+v[5](t)], t = 0 .. 1.5);

My problem is that, I do not know a priori which quantity I want to plot, and plotting using above method requires solving the ODEs each time separately, which takes a long time.

So I was curious if there is a scheme that I can solve my system for once and for all, and then plot any quantities that I would like to see.

guys, is there any possibility to obtain field equations of einstein-hilbert action?

best regards

How to compute Eigenvalues and Eigenvectors of the matrix over finite field? Thank you very much

Dear all,

I want to plot for example cos(theta) from 0 to 2*Pi inside a circle at a radius R. The axis theta of the ploted function is at a radius R.

Is it possible ?

Thanks

Hello,

The idea: parameter "a" will have a new random value each 10 days.

The way I did it is working but it can get very long especially if I do it for a system of equations and for long time more than a year (365 days).

The code:

with(DEtools); with(plots);
n := 5;

for i to n do Ra[i] := RandomTools:-Generate(distribution(Uniform(0.1e-1, .5))); a[[i]] := Ra[i] end do;

b := 0.1e-2;

T := 10;

 eq := diff(L(t), t) = a*L(t)-b;

init[1] := L(0) = 100;
 sol[1] := dsolve({init[1], subs(a = a[[1]], eq)}, L(t), range = 0 .. T, numeric);

init[2] := L(T) = rhs(sol[1](T)[2]);

sol[2] := dsolve({init[2], subs(a = a[[2]], eq)}, L(t), range = T .. 2*T, numeric);

init[3] := L(2*T) = rhs(sol[2](2*T)[2]);
sol[3] := dsolve({init[3], subs(a = a[[3]], eq)}, L(t), range = 2*T .. 3*T, numeric);

p[1] := odeplot(sol[1], [t, L(t)], t = 0 .. T);

p[2] := odeplot(sol[2], [t, L(t)], t = T .. 2*T);

p[3] := odeplot(sol[3], [t, L(t)], t = 2*T .. 3*T);

p := display([p[1], p[2], p[3]]);
display(p);

Thank you

solve.mw

Hi all, I want to determine the roots of this figure that attached here. But the function has 5 parameters so the code doesn't work for it! Help me.

I have another question: The code that attached, determine the roots on horizontal axis, how could I find the values of root on vertical axis?In this figure I want to know the value of F(0) that cut the vertical axis?

Regards