Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Area of shadow : i have studied one way of solution by hand, but now in Maple ?
Note: for math illustrations : geogebra seems to be wel suited

I would like to plot a specific vector with an initial point of <4,3,-5> and a terminal point of <3,-1,4>. I have been searching through Maple Primes and Maple Soft.

M1 := 12.3:
M2 := 12.4:
M3 := 12.5:
R := 50:

EQ:={(diff(F(x), x $ 4)) - M1*diff(G(x),x$2) -2*R*F(x)*diff(F(x),x$3)=0, diff(G(x),x$2)+ M2*(diff(F(x),x$2)-2*G(x)) +M3*(diff(F(x),x)*G(x)-2*F(x)*diff(G(x),x))=0}:

IC:={D(F)(-1)=0, D(F)(1)=0,F(-1)=-1,F(1)=1,G(-1)=0,  G(1)=0}:

sol:= dsolve(EQ union IC,numeric,output=Array([-1,-0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1]));
Error, (in dsolve/numeric/bvp) uanble to achieve continuous solution with requested accuracy of 0.1e-5 with maximum 128 point mesh (was able to get 0.47e-5), consider increasing `maxmesh` or using larger `abserr`

Error, (in plots/odeplot) input is not a valid dsolve/numeric solution
plots:-odeplot(sol,  [x, diff(F(x), x)], x = -1 .. 1, color =  green, axes = box)
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution
plots:-odeplot(sol, [x, G(x)], x = -1 .. 1, color = blue, axes = box);
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution


solve( sum((1/(1+x+x^2))*y^n, n=1..infinity) = 1, parametric=true, real);


How to solve two variables summation equation with parametric true or real triangularize?

how to solve for x and y?

I just wonder how it is possible to store data between sessions. What I found out is that if a matrix is connected with a datatable, the matrix data is stored. If it is not connected with a datatable, it is not.

In the attached example there are 2 matrices. If you run the worksheet, both variables are defined as visible in the variable overview.

After reopening without running the worksheet, just the variable connected with a datatable is.

Any ideas how to also get the second variable stored between sessions (obviously not with the same method as used for a)?


Download Analisa_Dinamik_Limb_v1_(30).mwAnalisa_Dinamik_Limb_v1_(30).mw

So I have an equation that basically takes the component of vectors to be used as an equation. The variables that I after are FB1z, FB2x, and FB3y For example here is my equation: 





However there are unknown variable in AFB2[1] named FB2x and AFB3[1] named FB3y. Then AFB1[2] has unknown equation named FB1z and AFB3[2] has FB3y and so on. While in my FBBp1,FBBp2,and FBBp3 holds all of the variable of FB1z, FB2x, and FB3x
I have tried to use 'solve' command to find the variable but my computer won't stop processing it:

I tried to use the Gauss-Elimination by forming a matrix but it doesn't work as well since I am really confused how to take out the variables out of the vector component.


I would be very grateful If someone could help me. Thankyou


Edit: here are the .txt files and .mpl files that required to run the program


Download DisplacementXYZ.txt


There is an .mpl file that I couldn't upload so I will upload it in the comments


I have to find the distance between a point and a plot. The point is (2,-3,4) and the plane is x+2y+2z=13. How do I plot this?

An attempt to find the equation of an ellipse inscribed in a given triangle. 
The program works on the basis of the ELS procedure.  After the procedure works, the  solutions are filtered.
ELS procedure solves the system of equations f1, f2, f3, f4, f5 for the coefficients of the second-order curve.
The equation f1 corresponds to the condition that the side of the triangle intersects t a curve of the second order at one point.
The equation f2 corresponds to the condition that the point x1,x2  belongs to a curve of the second order.
Equation f3 corresponds to the condition that the side of the triangle is tangent to the second order curve at the point x1,x2.
The equation f4 is similar to the equation f2, and the equation f5 is similar to the equation f3.
For example


i need to find a y(2) and than work with it in a loop

but i cant do it because i solved my equation with "dsolve" and "sol(2)" and its solution is list

really need a help


I am a new user to maple and I have tried to solve a partial differential equation.

The solution is shown in the figure above but I don't know how to make a 3d plot or contour plot of the solution. The code of solving pde is down below:

pde := diff(T(x, y), x $ 2) + diff(T(x, y), y $ 2) = 0;
bc := T(0, y) = T1, T(a, y) = T2, T(x, 0) = T2, k*D[2](T)(x, b) = h*(-T(x, b) + T3);
sol1 := simplify((pdsolve([pde, bc], T(x, y)) assuming (0 < a, 0 < b)));

and the constant value are:  a = 250, b = 4, k = 2.091, T1 = -5, T2 = 0, h = 100, T3 = 1000

the plot range is 0<x<250, 0<y<4.

Thank you for helping me!



From another question I asked, I learned that parse("string") returns an unevaluated Maple expression. 

But in interactive mode (in worksheet), the result looks the same as normal evaluated expression. That is why I did not know this. For example

ode1:= :-parse("diff(y(x),x$2)=0");
ode2:= diff(y(x),x$2)=0;

it gives

There is no difference when looking at it.  That is why when I was in Maple debugger, I could not see why Maple was complaining about it. An eval  was needed.

I looked at the types to see if there is something like type(variable,`unevaluated`) or such, and could not find one.

If Maple can at least display unevaluated expression with different color, or different notations when in the worksheet interface,  I would have noticed that parse returns unevaluated expression.

In Mathematica, these things are done using wrappers, (called Hold or Inactive) but these are visible in the notebook and use different color shading or Hold is present and had to expliclity removed,  and so looking at them, one can see the differerence between the expressions. 

How can one in Maple distinguish between unevaluated expression such as ode1 above and evaluated one such as ode2 above?  This can be useful to use inside a proc for example.  Is there an option in the GUI itself to tell Maple may be to color each differently?


According to the help manual...

To perform an action when the data table is updated, click the data table, and then, from the Data Table context panel, select Edit Content Changed Code to open the Code Editor dialog for the data table.

I am unable to make this work, nothing happens when I click on that button.

Edit - Component code - shows everything greyed out.

Any hints?

I can't figure why dsolve and odeadvisor fail to process ode when it is parsed from string and only inside a proc, but works ok in global space.

This works OK:

ode  :=  :-parse("diff(y(x),x$2)=0"):
func := :-parse("y(x)"):


But the same code, when inside a proc, fail

  local ode,func;  
  local x,y; #adding this did not  help

  ode  :=  :-parse("diff(y(x),x$2)=0");
  func :=  :-parse("y(x)");

     error lastexception;
  end try;

end proc;


It seems to have with name scoping, but I do not see what is the problem. :-parse works fine.

How to resolve this? Since I must use :-parse as I am reading the ode as string from database with Maple as string from inside a proc inside a module and the above is just a simple example that shows the problem.

Maple 2020.1 with Physics 724

I know for ordinairy differential equations (ODE) there is a odeadvisor in Maple what shows information about the equation .

What is is possible with a partial differential equations (PDE) package.
Is there a help like for ODE's ?

The following is my code, it is working but when I add third model in pde1 , it is not working .

Note that: u :people move to right,w: move to left,v: infected people and stationary(not move)

please help me to reconize the problem

pde1 := {diff(u(x, t), t) + Gamma*diff(u(x, t), x) = mu(w - u) - 0.5*beta*v*(w - u) - beta*u*v, diff(w(x, t), t) - Gamma*diff(w(x, t), x) = mu(u - w) - 0.5*beta*v*(u - w) - beta*w*v,diff(v(x,t),t)=beta*u*v-alpha*v};
IBC1 := {u(0, t) = 0, u(x, 0) = exp(-200*(x - 0.4)^2), w(1, t) = 0, w(x, 0) = exp(-200*(x - 0.6)^2),v(x,0)=0,v(0,t)=sin(t)};
mu := 0.0009;
Gamma := 10;alpha:=1;beta:=0.1
pds1 := pdsolve(pde1, IBC1, numeric, time = t, range = 0 .. 1, spacestep = 0.001);

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