Hey

Can anyone help me with this file?

I don't know how it happend, but the file somehow got corrupted. Is there anything i can do?

Thanks 

Videregående_beton_Gang_9.mw

I have a parametric polynomial which is defined based on the multiplication of different variables and I want to rearrange the polynomial based on specific variables. For example, suppose the polynomial is defined as follows:

a:= (1+x+y)(2x-yx+z)(y^2-zy)

and I want to have a based on first, and second orders of x, or even other variables. Thanks

Hi, my problem is the next differential equation:

In maple. I used this code to solved it, but throws this error:

dsolve({diff(y(x), x, x) = -P*x/(I*E), eval(y(x), x = L) = 0, eval((D(y))(x), x = L) = 0});
Error, (in dsolve) found differentiated functions with same name but depending on different arguments in the given DE system: {y(L), y(x)}

What is the problem with my code? How can solve my ODE with tis boundary conditions? 

How to write down the differential equation for this practical question? 

I can use dsolve to solve the system equation. 

Thank you! 

EDIT TIME: 14:30 CET

where P(1) and P(2) are NxN matrix functions.

My trial code for STEP 0

 alpha times integral w.r.t. x

 Int_x__alpha:=proc(term,alpha): 
 return
select(has,term,x).P(alpha)^T.remove(has,term,x)
end proc: 

 alpha times integral w.r.t. t

Int_t__alpha:=proc(term,alpha):   #alpha times integral w.r.t. t
 return
remove(has,term,t).P(alpha).select(has,term,t)
end proc:

when I run the last procedure for the testing

 Int_t__alpha(Psi(x)^T.C. Psi(t),2);

I get

But it must be 

Because the multiplication is not commutative in Matrices. So, the last procedure must be corrected. 

DETAILS for the procedures:

-------------------------------------------------------------------------------------------------------------------------------------

MAIN QUESTION:

Suppose that we have a PDE as follows 

                                             ...(3)

subject to appropriate Initial and Boundary conditions.

-------------------------------------------------------------------------------------------------------------------------------------

STEP 1

• Find the highest derivative w.r.t. x and w.r.t. t. Then, Let the trial function be the summation derivative of these highest derivatives. I mean

Trial Function:                                           ...(4)

where Psi(x), Psi(t) are Nx1 vectors and C is a NxN matrix.

I can't write a maple code for selecting the trial function.  May be you can.

trial_function:=diff(u(x,t),x,t)=Psi(x)^T.C. Psi(t); 

# I deliberately used ^T instead of ^+ for Transpose.
# If I use ^+, the transpose sign doesn't appear in 2d output. May be you have an other idea.

-------------------------------------------------------------------------------------------------------------------------------------

STEP 2

• Integrate the Eq.4  w.r.t. t from 0 to t, we have

STEP2:=int(  lhs(trial_function) ,t=0..t)=Int_t__alpha(rhs(trial_function),1);


The code must be improved. Firstly, substitute t=s in lhs(trial_function) and then integrate s=0..t 

-------------------------------------------------------------------------------------------------------------------------------------

STEP 3

int(lhs(STEP2),x=0..x)= Int_x__alpha(rhs(STEP2),1);

The code must be improved.

-------------------------------------------------------------------------------------------------------------------------------------
STEP 4

• Integrate Eq.4 w.r.t x

-------------------------------------------------------------------------------------------------------------------------------------
STEP 5

• Substitute Eq. (5), Eq. (6), Eq. (7) to Eq. (3),
• I mean substituting  u_x(x,t), u_t(x,t), u(x,t) to PDE.

-------------------------------------------------------------------------------------------------------------------------------------

STEP 6

DOWNLOAD ALL MAPLE CODE: all_code.mw

How can I get Maple to simplify expressions into more meaningful forms?

For example, 

xc1 := -(2*Q*R1 + sqrt(4*Q^2*R1*RL - R1^2 + 2*R1*RL - RL^2))*R1/(4*Q^2*R1 + R1 - RL)

The numerator, under the radical, is more meaningful as sqrt(4 Q^2 R1 RL-(R1-RL)^2).

Similarly, the denominator can be simplified to Rs(4 Q^2+1)-RL.  

How do I get Maple to get me there?

Hi

I have constructed a model of an UR5e in maplesim with the hop to be able to test my controller writen in python on it. 

I hope to be able from the model to

• Enter a tourqvalue for the joints.
• Extract joint angles, joint velocitys as well as the forces and tourqes that affects the end effector.
• (If posible) visualize the sumulated robot arm so I can se that the motion reflects that of the real robot arm.

the simulated robot arm 

The question is how to best do this in a semi realtime way?

I have been looking into generating a FMU but if there are other ways to do this, then I am open to ides. 

The contorller is based on a haptic algoritm for connecting two robot arms and I will only get one robot arm due to prise and space constraints.

This means that I will reseave realtime information from the real robot arm into my python controller that then i supose to take inforamtion from the simulated arm and with information from both arms calculate the tourqe values for both arms joints. 

Thanks in advance for all youre help

Eric Ragnarsson

I am wondering if there are examples of agent-based models in economics domain that have been implemented in Maple.

Any infomration/source is more than welcome!

Thanks in advance

I actually want to numerically solve Karhunen-Loeve Decomposition, which is reduced to homogenous Fredholm integral equation second kind when the kernel is the function of correlation of variables, by using any procedures (Galerkin is better if it is availabe). FYI, with "intsolve" I just got f(x)=0. 

I am a newbie in Maple! I tried both ThermophysicalData and its CoolProp package to find saturation pressure of vapor for given air-water mixture temperature.

I want to calculate water vapor density in air or simply Absolute humidity (kg/m3)

But i can not see any meaningful function or combination of functions/properties in CoolProp to give such output.

P_w in CoolProp, HApropSI takes this as input only that is not usefule either way inpoutput

The rationale is to work from RH and then calculate P_w as output: P_w=RH x P_g where P_g is vapor saturation pressure at the given ambient condition.

From there all world is yours!

You can use ideal gas rules to do everything. But i cant use CoolProp to calculate the ABsolute humidty for given RH and ambient condition.

Note that clearly i can calculate all these from hand calculation as well as approximation formuale of Clausius-Clapeyron equation. But i wanted to do in Maple with its packages.

Any help is appreciated!?

Regards

Sina

Hi

I have the following fractional  system of differential equation. How to plot it for alpha=0.5, beta=0.5?

eq1:=diff(y1(t),t$alpha)=0.04-(0.09*y1(t)*y2(t))-(0.00250*y1(t)*y2(t))/((0.03500+y2(t)))-0.04*y1(t);                                                                                                                                                                    

eq2:=diff(y2(t),t$beta)=(0.09*y1(t)*y2(t))+(0.00250*y1(t)*y2(t))/((0.035+y2(t)))-(0.02+0.04)*y2(t);

Hi, 

Whenever I open Maple 2020 and type one single letter or number (doesn't matter) Maple 2020 will "freeze" and load forever (i have had it open for a long time, just watching that f**king blue circle spin...

I have tried reinstalling, repairing, running as admin, and changing the compatibility mode, still, nothing works:(

I run Maple 2020 as a Student with WithGym

Pc specs:

Intel i5-10300h 2.6 ghz

Geforce 1660 ti 6gb

Windows 10 x64

Is it possible in one worksheet of a workbooks to access variables or embedded components in another worksheet programmatically?

As far as I can see it is possible to save and restore variables through the variable browser, so it is also possible to get them from one worksheet to another. This is however done by the user.

Now the question is, if it is somehow possible to e.g. access the contents of a embedded component like a Combobox in a different worksheet of the workbook - without opening the worksheet first?

[[1,1,["ab","xy"]], [0,1,["xy"]]]
 

how to sort by first number , second number , and list of string ?

how to count and group by third list of strings having first two number 0,0 or 0,1 or 1,0 or 1,1 

for example 

["xy"] at most count 4  , at least count 1

would like to find which is [1,1,... ] and only count 1

Suppose we have a 200-litre tank. Suppose 10 litres per minute of salt water (brine) flows into the tank at the top, it mixes perfectly with the contents of the tank, and 10 litres per minute of the mixture flows out of the tank at the bottom. Assume for simplicity that the salt water in the tank is stirred so that its concentration is uniform in the tank. Let S(t) be the amount of salt, in grams, in the tank at t time minutes. Suppose the salt water flowing into the tank has concentration 80 grams per litre.

Find the differential equation to model the change in S(t).

Assuming that at t = 0 time the concentration of salt in the tank is 10 grams per litre, solve the differential equation using Maple.

What is S(infinite)? That is, how much salt is in the tank after a long time?

Now graph S(t) for a suitable domain so we can see the function approaching the value S(infinite)

---------------------

Have some difficulty to understand the problem. I mean, such modelling problem rather than pure math computation.

Thank you so much!