Unanswered Questions

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

write down the mapple procedure that finds the shape operator plus
gauss and primative curvatores and determines the surface characteristic
of a parametically given surface

 

best regards, ty

Dear All, I need your help to plot the numerical solution. many thanks.

The variable t in [0,T], x in [0,1], b in [0,2].

Difference finie for waves equation is :

pde:=diff(u(x, y,t), t$2) = c^2*(diff(u(x, y,t),x$2)+diff(u(x,y,t),y$2));

i: according to x, j according to y, and k according to t.

u[i,j,k+1]=2*u[i,j,k]-u[i,j,k-1]+(c*dt/dx)^2*(u[i-1,j,k]-2*u[i,j,k]+u[i+1,j,k])+ (c*dt/dy)^2*(u[i,j-1,k]-2*u[i,j,k]+u[i,j+1,k])

 

Boundary condition: u(t=0)=1, diff(u(x,y,t),t=0)=0, and the normal derivative on the boundary of Omega =0.

How can solve this problem and plot the numerical solution.

 

 

 

I am trying to write a procedure that have the following input:  expr, xdata,ydata. [dependent variables list]

I want a procedure to calculate Rsquare following the method described in 

http://www.mapleprimes.com/questions/120014-How-To-Calculate-Coefficient-Of-Determination

 

But I want the proc to take any abitary function and be able to identify the  dependent variable...how can I approach it? what function can I use to match [dependent variable list] in expr??

 

Thanks

 

 

I have a question regarding maple reader.

 

It seems like in maple reader, one cannot interact with the output of the Explore function.... which mean I am forced to make my own component if I want to creat application for my co-worker to use..this is some what annoying.  Is there another way around?

 

please open the attached file in maple player and you will see the output created by Explore gives error message.  mapleplayer_test.mw

 

Download mapleplayer_test.mw

.  

Pls, I tried solving the system of PDE numerically.... When I did for just 1 plot, the graph was plotted easilyrunning.mw but When I varied some parameters its not coming out.... Also, its not bringing any error so I can't trace out my mistakes....Not_runnin.mw PLS HELP ME OUT with the multiple plots... Attached are my source codes links....

 

When using Maximize, is it possible to now what parameter settings that resulted in complex numbers?

KR Fredrik

 

Maximize(Eq1_new, {R_K*rho*`&sigma;_K`+R_S*`&sigma;_S` >= .38780613588076011954, r_K*rho*`&sigma;_K`+r_S*`&sigma;_S` >= .21290471165685214846, R_K*rho*`&sigma;_K`+R_S*`&sigma;_S` <= .38780613588076011954, r_K*rho*`&sigma;_K`+r_S*`&sigma;_S` <= .21290471165685214846});


Error, (in Optimization:-NLPSolve) complex value encountered


intsolve(int(f1(u)*(x-y), u = a .. b) = (12)*cos(x)+5*x^2-12, f1(x));I try to resolve the integral equation but i received all the time the followinf message error 

Error, (in intsolve) invalid input: rhs received {f1(x) = ?}, which is not valid for its 1st argument, expr
I try to use different form but i do not how to resolve the help center do not help to much.

I preciate any help thanks

 

Hi.

please, I need some code about stepsize adaptative Runge Kutta method ( any order ) or other methods.

Thanks

i cant find the error the program is saying i have 

> L := -1.576674; MU := 0; DE13 := {D(y)*t = -x(t)*(1-2*x(t)*x(t))+MU*y(t)*(x(t)*x(t)-3*y(t)*y(t)-L), (D(x))(t) = y(t)*(1-y(t)*y(t))+MU*y(t)*(x(t)*x(t)-3*y(t)*y(t)-L)}; DEplot(DE13, [x(t), y(t)], t = -20 .. 20, [[x(0) = 0.1e-1, y(0) = .99], [x(0) = 0.5e-1, y(0) = .95], [x(0) = .1, y(0) = .9], [x(0) = 0.4e-1, y(0) = .96]], stepsize = 0.1e-2, scene = [x(t), y(t)], title = "phaseplane plot", linecolor = black, thickness = 1, number = 1000);
 
Error, (in DEtools/DEplot/CheckInitial) too few initial conditions: [x(0) = 0.1e-1, y(0) = .99]

it might be hard to read but if someone could help me it would be very appreciated 

Hi

I need a temperature distribution inside a barrier during a heating process.
I will be appreciated for any help.

 

wz

How to animete BC using varying temperature in time?  How to obtain animated solution?

restart

Diffusivity coefficent...

a := 0.1e-5:

Thickness of barrier...

L := .2:

Heating curve:
Time in heating curve (in hours form exmaple)...

Time := seq(i, i = 1 .. 10):

Varying temperature in time [K]....

Temp_in_Time := [433.15, 568.15, 703.15, 838.15, 973.15, 1108.15, 1243.15, 1378.15, 1513.15, 1616.15]:

Initial temperature [K]

Tot := 298:

PDE := diff(T(x, t), t) = a*(diff(T(x, t), x, x)):

--->>>

BC1 := {T(0, t) = Temp_in_Time[2], T(L, t) = Temp_in_Time[2], T(x, 0) = Tot}:

sol := pdsolve(PDE, BC1, numeric, timestep = 50):

sol:-plot(t = 3*3600, thickness = 3, colour = red);

 

``



Download heating.mw

restart:

Eq1:=1/r*diff(r*diff(w(r),r),r)-(cos(z1))^2*(w(r)+1)-DP;

dsolve({Eq1});

bcs:=D(w)(0)=0,w(r2)=A1;

dsolve({Eq1,bcs},w(r)):

where z1, Dp, r2, A1 are constants.

 

Hi, i'm wondering if theres anything i can do printf and print and have the outputs on the same line. I want the string wihtout any quotations so i think i can only do printf to get this, but then i'm putting an entry out of an array after this. This is a small example out of my code, i would like the output to be all on one line:

The synchronising vector is (S[j-1]) The synchronising word is (X[j-1]) The length of the synchronising word is ...

 

if (sync=true) then 
printf("The Synchronising vector is"); print(S[j-1]);
printf("The sychronising word is");
print(X[j-1]);
printf("The length of the synchronising word is");
print(length(X[j-1]));
else printf("There is no synchronising word"); 
end if;

 At the moment its outputing each print on a new line.

Any help would be much appreciated, thanks.

 

hi all.
i have a system of ODE's including 9 set of coupled OED's . 

 

for example

a*b v a^-1 = b

i guess Disj or Conj are Max or Min respectively

however i do not know how to max(a,b) where a and b are permutation group

reference from L group in 

http://books.google.com.hk/books/about/Lattice_Ordered_Groups.html?id=_qAFX38-pKkC&redir_esc=y

 

if can not calculate this, do not know how to determine whether equal in a*b v a^-1 = b

I came to know that Chrome no longer supports MathML. Will this be an issue with Maple T.A.9/9.5? Should I require my students to switch to Firefox instread? 

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