I've been trying to make a smooth plot of some ODEs. It should show C rapidly increasing at the innitiation, until they get into a quassi steady state,  and then all three variables increase much slower. This should look like a roughly straight line that elbows sharply into a smooth curve.

Any attempt to DEplot3d it i've made either just shows the time before the quassi steady state is reached, so shows the straight line; or smooths that time together with the next period, making the straight line look like a part of the smooth curve.

Model := [diff(B[1](t), t) = k[a1]*C(t)*(R-B[1](t)-B[2](t))-k[d1]*B[1](t), diff(B[2](t), t) = k[a2]*C(t)*(R-B[1](t)-B[2](t))-k[d2]*B[2](t), diff(C(t), t) = (-(k[a1]+k[a2])*C(t)*(R-B[1](t)-B[2](t))+k[d1]*B[1]+k[d2]*B[2](t)+k[m]*((I)(t)-C(t)))/h];
DissMod := subs((I)(t) = 0, Model);
AssMod := subs((I)(t) = C[T], Model);


Pars := [k[a1] = 6*10^(-4), k[d1] = 7*10^(-3), k[a2] = 5*10^(-4), k[d2] = 10^(-2), R = .5, k[m] = 10^(-4), C[T] = 100, h = 10^(-6)]

StateSol := DEplot3d(subs(Pars, AssMod), [B[1](t), B[2](t), C(t)], t = 0 .. 1000, number = 3, B[1] = 0 .. .5, B[2] = 0 .. .5, [[B[1](0) = 0, B[2](0) = 0, C(0) = 0]], scene = [B[1](t), B[2](t), C(t)], maxstep = .1, maxfun = 0, method = l)

Is there a way to display the list of coordinates for implicitplot and plot, rather than the displaying image itself?

In Maple Classic this happens automatically when the assignment operator is used  ( := ) together with a semi-colon, eg.   A:=implicitplot(F, x=-1..1, y=-1..1);

But is there a way to do this in the non-classic version?  Thanks very much.

- Graham

Hello fellow maple struglers!

This is my first question, so hopefully I did it in the correct manner. My problem (I think) is of a simple nature, but I can't seem to get it to work. The equation I have is the following:

All is nice and well and as you all can see it depends on two variables. Now what I want to do is to express the function in a shape where it depends on the ratio t/d only. Simple calculus shows that for this equation it is rather easy, where the result is:

(62,8*t/d+0,0945)/pi

Now I would like to know whether it is possible to automate this in maple, such that I can plot Wr_over_p as a function of t/d. I know I can simply use the form above and make the plot, but further down in my maple file I have an equation which is much more complex, and I want to plot thatone as a function of t/d as well.

I hope I have made my problem clear to some of you guys, but if you require some further explaination than please let me know. Thanks in advance for your help, I hope there is someone who can help me with this!

I have two deformed planes, that i would like to draw with 3dplot, as well as drawing a curve marking their intersection.

the curves are given by the expressions:

C = -(k[d2]*B[2]+I*k[m]+k[d1]*B[1])/((B[1]+B[2]-R)*k[a1]+(B[1]+B[2]-R)*k[a2]-k[m]),

C = k[d1]*B[1]/(k[a1]*(R-B[1]-B[2]))

evaluated at

Pars := [k[a1] = 6*10^(-4), k[d1] = 7*10^(-3), k[a2] = 5*10^(-4), k[d2] = 10^(-2), R = .5, k[m] = 10^(-4), C[T] = 100, h = 10^(-6)]

with the variables B[1],B[2] and C within the bounds [0..0.5],[0..0.5],[0..100].

My method was to try and use solve to find a formula for the intersection curve- but i couldn't get 3dplot to plot it!

Consider the following code snippet:

with(DifferentialGeometry):
DGsetup([x],M);
RemoveFrame(M);

By itself it is, of course, pretty meaningless, but that is not the point. My problem is that after Maple has executed it, it will annoyingly continue using M> for each new execution group that is inserted. Having removed the frame with the command RemoveFrame, I would have expected that not to be the case. How can the frame be truly removed?

hi. i have a system of ODEs. is there any answer ? rho is constant !

Download dsolve.mw

Hi, I have this procedure (from Maple 5) but I am using it in Maple 15. My problem is this program can not run. I think there is some commond incorrect, but not sure which ones. Please help me in this problem. Thanks a lot.

cocycle.mw

Download cocycle.m

in Mathematica, there is the option called BoxRatios

"is an option for Graphics3D that gives the ratios of side lengths for the bounding box of the three‐dimensional picture."

It is sort-of like aspect ratio, but for 3D. It is set by default so make 3D plot looks "nice". I can't seem to find equivalent Maple option. The closest is the option "s=" for plot3d, but this just turns of/on "constrained scaling" and does not allow one to modify the "BoxRatios"

Let me give an example. Here is 3D plot in Mathematica and the same in Maple. I'd like to get the Maple 3D to look similar to Mathematica 3D in terms of the "aspect ratio". Maple on the z-axis is using the same size as in the x and y axis, and even though this is realistic, it does not make the plot as nice. I want to change this ratio.

T0[x_, y_, m_] :=20/Pi Sum[ (-1)^(n + 1)/n Exp[- (n Pi/10) y] Sin[ (n Pi/10) x], {n,1, m}]
Plot3D[T0[x, y, 70], {x, 0, 10}, {y, 0, 10}, PlotRange -> All,  AxesLabel -> {x, y, z}]

In Maple:

T0:= (x,y,m)-> 20/Pi*sum( (-1)^(n+1)/n*exp(- n*Pi/10*y)*sin(n*Pi/10*x),n=1..m);
plot3d(T0(x,y,50),x=0..10,y=0..10,scaling=unconstrained);

So Maple is using 1:1:1 box ratio. Mathematica default is 1:1:0.4, and I wanted to see if I can change Maple to be the same.

I get same plot in Maple using scaling=unconstrained or scaling=constrained. So this option is not very useful for what I want.

Is there a way to change the "BoxRatios" as defined above in Maple? There must be, right? Do I need to use different package?

Dear All

In following I tried to find symmetries of certain partial differential equation taken from paper "Group classification and exact solutions of generalized modified Boussinesq equation". But the determining equations are not matching with equations obtained in paper.

Download [1116]_Symmetries_Determination.mw[1116]_Group_classification_and_exact_solutions_of_generalized_modified_Boussinesq_equation.pdf

Regards

Still a little unclear what this error means tho

Download dispatchTOshillCORE.mw

yep the errors recieved using some packages are very very specific for maple, for example, the one i got today using the ODE package was profoundly helpful:

Error, (in ODEtools/info) unable to handle derivatives as {diff(1/(ln(X)-Psi(1-f(X))-Psi(f(X))), [`$`(X, n-k[1]-k[2])]), diff(1/f(X), [`$`(X, n-k[1]-k[2])]), diff(Psi(1-f(X)), [`$`(X, k[2])]), diff(Psi(f(X)), [`$`(X, k[2])]), diff(f(X), [`$`(X, k[1])])} while solving w.r.t f(X)

im refering to the reason why a maple andriod application hasnt shown up or at least one of the big ones (preferably a java based on since thats the only thing i know for making any apps fluently) but yep cannot be the only one who has felt that need to get out of the house but wants to keep mathing when there is nothing to do which is pretty much always for me anyway

How can one find out when a Maple command or package became part of Maple? i.e. which Maple version first had this command or package?

For example, I'd like to know when applyrule https://www.maplesoft.com/support/help/Maple/view.aspx?path=applyrule was introduced. But this applies really to any command I see.

In Mathematica, this is easy to find out, since it is documented in the help page for the command, at the botton of each page when the command was added. Is there a command or a web page that shows this type of information about Maple commands and packages?

I have some data

> X:=[291.3301386,349.9410125,420.7945287,490.0836935,558.1365585,623.6824877,688.6344191,752.1359797,814.1871695,874.7879884,933.8452525,991.0023402,1047.88822,1102.687556,1156.036521,1207.200419]:

>
> Y:=[0.008923638,0.010336322,0.012031554,0.013676089,0.01527851,0.016809936,0.018315901,0.019777093,0.021194266,0.022568158,0.023897399,0.025174796,0.026437267,0.027645069,0.02881302,0.029925828]:

to which I am trying to fit a function

U:=(m,d,Theta,T)-> (((3*(6.62607e-34)^2*T)/(4*Pi^2*m*1.36085e-23*Theta^2))*((T/Theta)*int(x/(exp(x)-1),x=0..Theta/T) + (Theta/(4*T))))/1e-10^2 +d^2;

where Theta≈200 and d≈0.035. T, Theta, d, m > 0

 When I try and solve

> NonlinearFit(U(0.15036/6.022e23,d,Theta,T),X,Y,T,initialvalues=[Theta=200, d=0.035]);

I get the error "Error, (in Statistics:-NonlinearFit) complex value encountered"

I can plot the function with Theta=200 and d=0.035, I get approximately the right curve and no errors about complex values.

How can I solve for Theta and d without encountering this error?

Hello,

Lets say I have some expression F that is a function of n and N like, F=n+N-1 and I want to express that in terms of x, where x=n/N. How would I do this in maple? Thanks in advance.