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)?

storetable.mw

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: 

EOM1:=(AFB1[1]+AFB2[1]+AFB3[1])=TEOM[1]

EOM2:=(AFB1[2]+AFB2[2]+AFB3[2])=TEOM[2]

EOM3:=(AFB1[3]+AFB2[3]+AFB3[3])-TEOM[3]:

FBBp1:=FBPP1=(EulP1[1]+EulP2[1]+EulP3[1]):
FBBp2:=FBPP2=(EulP1[2]+EulP2[2]+EulP3[2]):
FBBp3:=FBPP3=(EulP1[3]+EulP2[3]+EulP3[3]):

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:
sls:=solve({EOM1,EOM2,EOM3,FBBp1,FBBp2,FBBp3},{FB1z,FB2x,FB3y}):

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.

zzz:=Matrix([0,AFB2[1],AFB3[1],jjj[1]],[AFB1[2],0,AFB3[2],jjj[2]],[AFB1[3],AFB2[3],0,jjj[3]],[FBP1[1],FBP2[1],FBP3[1],EulP[1]],[FBP1[2],FBP2[2],FBP3[2],EulP[2]],[FBP1[3],FBP2[3],FBP3[3],EulP[3]]):
GaussElimination:=(zzz)

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 

Inverse_Kinematics_ADRIAN2.mw

RotInertiax0_ADRIAN.txt

Download DisplacementXYZ.txt

inersia_platfrom.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?

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

Hi!

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:

restart;
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:

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

dsolve(ode);
DEtools:-odeadvisor(ode,func);

But the same code, when inside a proc, fail

restart;
foo:=proc()
  local ode,func;  
  local x,y; #adding this did not  help

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

  dsolve(ode);
  try
     DEtools:-odeadvisor(ode,func);
  catch:
     error lastexception;
  end try;

end proc;

foo()

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

restart;
with(PDEtools);
with(plots);
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);
 

I cannot seem to set up this integral correctly:

Gradshteyn 3.529

I think maple should do it.

`assuming`([int(((cosh(a*x)-1)/sinh(b*x))(1/x), x = 0 .. infinity)], [b > abs(a)])

I wonder where I'm going wrong here? Thank you in advance.

hi

I'm working on my thesis,to solve a particular problem,I created a 84*84 matrix in Matlab.

I want to calculate the determinat of that matrix in maple,so from tools>assistance>import date added this matrix in maple.

every thing seems to be ok but when i want to caculate the determinant this error apears :

 Error, (in LinearAlgebra:-Determinant) matrix must be square

does anybody know what is the problem here?

Also sorry for my weak English 

and it's worth mentioning that I'm a beginner in maple programming 

thank you

Since I've updated maple to version 2019 it's has become very slow. Erverytime I enter something it seems to reload all the side buttons just like when a new worksheet is started. This is very annoying because during this loading time you cannot enter anything. Has anyone any suggestions? btw I've bought my pc in march 2020 and it has enough CPU and GPU.

i have a nonlinear inequality which is plotted using plots:-inequl
can i find an algebric solution for this inequality? for example sth like this : 0.08<t<10 
thnx in advance

 

Download inequality.mw