Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

I have a plot of a sinusoidal function(cos_phi) which changes with incrementing values of variable k. When this function goes above 1 or below -1 I would like to have the range of k for which it occurs outputed somehow. Would anybody know how to do this?

I am having trouble printing out a limit cylce on maple 16.  I have the attached file and if anybody could look at it and perhaps help me out it would be greatly appreciated.  The first limit cycle is supposed to look somewhat like the second one.  I'v tried many different things but nothing seems to be working.  an explenation would also be nice too.  if the file does not open correctly also let me know. thank you very much.  

 Math_4710_Hilbert_16.mw

Hi , i need to write some maple functions for the equations below and i am not sure if this should be arrays or not. please see the question below;

Consider a factory which manufactures only one product. Raw material is bought from external supplier and stored until required.

Finished items are held in a warehouse. The operation of factory and its warehouse

can be modelled as a set of equations as folllows.

 Let us define at time t :

R(t) = Raw material stored (units)

F(t) = finished goods stock (units)

B(t) = order backlog (units)

T(t) = target stock level for finished goods (units)

 

All variables defined above give quantities at the start of week t.

 

X( t, t+1 )= weekly orders received from customers

M( t, t+1 )= raw material supplied per week.

P( t, t+1 )= production per week.

D(t, t+1 )= amount dispatched to customers per week.

 

All variables defined above give quantities over week t to t+1

(i.e over the week t). The operation of the factory and its warehouse can be expressed

as a set of equations given as follows:

 

Backlog and Stock Position

(1) B(t+1) = B(t)+X (t,t+1)–D(t,t+1)

(2) T(t+1) =(m +1)/m(X(t,t+1)+X(t–1,t)+…+X (t–m+1,t–m+2))

 

(assuming that the company wishes to maintain m (suppose m=5)) weeks stock of

finish items and hence the target level is m times the average of the last m–1 weeks)

(3) R (t+1)=R(t)+M(t,t+1)–P(t,t+1)

(4) F (t+1)=F (t) +P(t,t+1)–D(t,t+1)

Rates

(5) D (t,t+1) = B(t) if B(t)<F(t)

F (t) otherwise

(6) M (t,t+1) = P(t–1,t)

(7) P (t,t+1) = T(t) – F(t) + D(t,t+1)

= R(t) if result exceeds R(t)

= 0 if the result is negative

 

Given the initial values for the variables, it is possible to simulate this system to study

how the system will respond to the order rate. Suppose that all is calm, and the factory

has operated as follows for the last five weeks.

Target warehouse stock = 250

Finished goods stock = 250

Raw material stock = 150

Production rate = 50/week

Material supply rate = 50/week

Order rate = 50/week

Order backlog = 50

 

Suppose the behaviour continues for the first week of the simulation but that during

next week orders double due to the sales promotion. During the third week orders

drops to zero as all demand returns of the previous week was satisfied. For the fourth

week and the succeeding weeks, demand returns to an order rate of 50/week. What

happens elsewhere in the system? A deterministic simulation will provide the answer

to the above mentioned question.

 

 For this compute the following.

i) The values of the equations (1)–(4) at the start of week t.

ii) The values of the equations (5)–(7) i.e. the new values of the rates during

the following week.

iii) Move simulation time to the start of the next week.

Next simulation should be presented in tabular form and plot production and demand

rate to examine the performance of the system.

 

All help will be much appreciated.

Best Regards,

 

I do not have any code to produce yet.  I want to have Maple animate a bouncing ball on some 3d surface.

and if the A are an inversable matrix

Hi

worksheet output doesnt display the eigenvalues of a 19X19 matrix. Just gives in the form Root of(...). when datatype is indicated as anything other than complex(sflot) it gives error "unable to store". solution is required in compact mathematical expression form (may involve square roots etc). Please help.

Thanks

When I try "touch and drag" in Maple documents, the documentation for example, I end up selecting text instead of scrolling. Unfortunately the alternatives for scrolling are a) the scrollbar, b) page-up/down or c) moving the cursor. Each of those alternatives is about 2.5311 orders of magnitude more inconvenient than touch&drag.

Does anybody know if its possible to get Maple (18) to scroll instead of select text when I touch the screen?

 

Hi everyone.

I'm trying to visualize some some field lines for a 3D magnetic field I have simulated, and I have read that the Student[VectorCalculus] package is the best package for this type of visualization. I tried implementing it as described online and in the manual, and I got an error:

Error, (in plots/fieldplot3d) no non-zero vectors found

 

Does anyone have any ideas as to what could be causing this issue?

Attached is the Maple document I am using. The section entitled "Problem Area" is where the issue is.

 

turtle-rec-bend.mw

Hello,

• Is there a simple way to find the domain for the real solutions of f(x)?

• And is there a way to let maple get the part of f(x) with the sqrt?
   (not by typing it by hand as I dit below)

• Is there a way to write the summary of the found domains in one line?

Thanks for your help. 





restart:
# How to find the Domain for real solutions for x?
f(x):=(x-1+sqrt(x^2-3*x+2))/(x-1);
discont_for_x=discont(f(x),x);
# x<>+1 (because the de denom=0 is not allowed)
denom(f(x))=0;
x={solve(denom(f(x))=0,x)};
# x<=1 union  2<=x (because the part under the sqrt must be >=0 to give Real solutions)
sqrt(x^2-3*x+2);
0<=x^2-3*x+2;
x=solve(0<=x^2-3*x+2,x);




Hi,

What is the reason/Why: 

 

Error, (in dsolve/numeric/bvp) unable to achieve requested accuracy of 0.1e-5 with maximum 128 point mesh (was able to get 0.66e-1), consider increasing `maxmesh` or using larger `abserr`

Thanks for the help :)

I'm trying to plot the direction field of the second order differential equation x''=x'-cos(x) using dfieldplot: 

> with(DEtools); with(plots);
> f1 := (x, y) options operator, arrow; diff(x(t), t)-cos(x(t)) end proc;
/ d \
(x, y) -> |--- x(t)| - cos(x(t))
\ dt /
> dfieldplot([diff(x(t), t) = y(t), diff(y(t), t) = f1(x(t), y(t))], [x(t), y(t)], t = -2 .. 2, x = -2 .. 2, y = -2 .. 2);
Error, (in DEtools/dfieldplot) cannot produce plot, non-autonomous DE(s) require initial conditions.
>

The error I'm getting says I need initial conditions, but I wasn't provided with any. Is there another way to plot this? Sorry if this is dumb question, but I've only ever plotted first order equations.

Does anyone has any maple worksheet that generate surface using the PDE method described in this article?  I am trying to learn this method but I am not familiar with the mathematics to do it although the paper gives some description of it.  I hope someone can demonstrate the procedure in Maple.  Thanks

http://www.researchgate.net/publication/259095177_Automatic_shape_optimisation_of_pharmaceutical_tablets_using_Partial_Differential_Equations/file/72e7e52a87ed129d4a.pdf

I need to maximize two multivariate objective functions (f(x1,y1,z1,t1) and g(x2,y2,z2,t2)) with inequality and nonnegativity constraints (x1, x2>0 and y1, z1, t1, y2, z2, t2 >=0). I am looking for parametric not numerical solutions.


What is the best way to find the solution to such a problem using maple?

Hi

I want to create a linearied model for a single or multi degree of freedom vibration system by MapleSim. i faced a lot of problem such as causalize ports, i search the user manual but i didn't find it useful. i attach a very simply one degree of freedom vibration system. i wondering if every one create a linearized model for it. my final goal is governing the equation and determine the natural frequency with nyquist plots. i have mapleSim 6.2 and Maple 17. Thanks

 

prob1.msim

When trying to solve a set of partial differential equations, I always get the following error. I don't know what it means. Can somebody help me?

 

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