Hello everyone!

I'm working with Maple for 8 years and this is the first time I encounter such a problem:

I solve a linear ODE system for my quantum Mechanics research and i want to calculate a quantity formed by the solutions of the system. Everything is going fine with laplace transformation and the symbolic answer is very fast although extremely big (it uses RootOf simplification)

When i use evalf to take numerical approximations of the quantity, the answer is very fast. OK

When i leave unspecified two parameters in order to get a 3d plot the answer takes about 40mins to appear. I think it is too slow but anyway, i can live with it. OK

I want this 3d plot for different parameters of the ODE so i have to do the above process many times. But for some parameter values of the ODE, i get a 3dplot for which:

1) The display of numpoints (surface and line) is incorrect.

2) Plot gets deformed as long as i rotate it!!! The orientation angle changes the appearance of the plot, something obviously unacceptable. I have access to maple 17, 15, 14, and 12. Maple 17 and 15 exhibit this behavior (64 bit Maple editions). But when i tried with Maple 12-standard interface(64 bit) and Maple 14 -Classical interface (32bit) everything went fine, but at the cost of  300 extra secs. I got a solid 3d-plot that is invariant under rotations.

My video card is Ati radeon 6800 HD and i installed the latest drivers. I don't know why is this happening. I thought of putting the blame on me, but in maple 12 and maple 14 everything is fine. It is a pity, because Maple 17 gives very nice and smooth 3d plots.

The first plot is the correct one with maple 12. The second is produced with maple 14. All good.

The third and the second are produced with different orientations of the same plot (Maple 17). Wrong display of data and change of image after rotation. The final one is again from Maple 17 but with style=points. It is in is in full agreement with the first two plots. 

Conclusion: Style=surface and line doesnt produce the correct plot, while style=point does. As for hardware acceleration, i unticked it with no results.

Extra information: When i try to open the maple 12 worksheet which is correct, with Maple 17, again i take the wrong displayed and unstable picture. Moreover only maple 14 classical edition works well. Maple 14 standard interface is also pathological.

Heeeeelp guys!!!

hi 

what is problem ?

Download u(x_y).mw

i want to define a loop for like this : 

for i from 0 to 100 by 0.2 do; ... ; od ;

i want when this loop finishes,the the loop turns to exactly vice versa respect,and continue , i mean it continue like this :
for i from 100 to 0 by -0.2 ...  , 

can anybody help me to find an algorithm for this ? tnx in advance

I am trying to color a sphere according to the following function and I am having some difficulties. Suggestions are appreciated.

((5x^2y^2)-6x^4)\((1-y^2)(x^2+y^2)-(y^2(1-x^2-y^2)).

Thank you

Dear people in Maple Primes,

I have a question about how to solve a system of equations.

In the following equation, I want to eliminate D(a).

x := D(a*b*c = 3*d); 
y := D(a^2*b^3*c = 3*a);

For this purpose,

a code of 

d_a := isolate(x, D(a));

eval(y, d_a);

works well. But, for me, this code is a little laborious.

Is there any better way than the above way?

Thanks in advance.

taro yamada

How to create a long progression in maple (up to 100 000 000 000), where a member is a previous one plus a certain number. For example: 25, 50, 75, 100... and then divide the whole series (all the members) by a number. What command should one use?

Hi all,

I try  to plot phase portrait the below DAEs, 

diff(S(t), t)=-β*(1+δ*sin2Πt)*S(t)*I(t)-μ*S(t)+μ,

diff(I(t), t)=β*(1+δ*sin2Πt)*S(t)*I(t)-γ*I(t)-μ*I(t),

0=S(t)+I(t)+R(t)-1.

where

μ=0.01,

β=1510,

δ=0.02,

γ=50,

I really appreciate your help.

a:=rand(0..8):
b:=rand(0..8):
c:=rand(0..8):
d:=rand(0..8):
e:=rand(0..8):
f:=rand(0..8):
a()+b()+c()+d()+e()+f()=8;

This is my  programming code.

I want ot set six random summation is  8. 

But the random summation can't reach 8.

Hi, 

  I would like to a string of characters to a file. For example,

***

str:="hello world";
WriteFile[APPEND]("D:\\output3.txt", str);

***

  It doesn't work. I did not get output3.txt :(  How should I do, to write a string of characters, such as "hello world" to a file?

Thank you

hi

please help me :

BC1 = diff(T(x, 0), y)=1000

BC2 = diff(T(x, 0.000025), y)=2000

IC = T(0,y)=0

where :

u(y)=-1.218493440*10^11*y^2+4.244913600*10^6*y+0.033

Download PDE_Sol.mw

qu.mw 

this is my code but there has smoe problom

i make the MathContainer0 and MathContainer1 can be entered number

 i plot the loop circle, and then i want to show te insection of two circle,that the center and radius of two 

 depends on the value of MathContainer0 and MathContainer1 that we entered

any one can help me? thx

I wrote a maple code and it returns: if statement error to me.

How can I fix it?

Regards

F1 := proc (rlist, deltalist) local sum1, i; sum1 := 0; for i to 8 do sum1 := sum1+rlist[i]*deltalist[i] end do; if `mod`(sum1, 24) = 0 then return true else return false end if end proc;

 F2 := proc (rlist, deltalist) local i, sum2; sum2 := 0; for i to 8 do if deltalist <> 0 then sum2 := sum2+40*rlist[i]/deltalist[i] end if end do; if `mod`(sum2, 24) = 0 then return true else return false end if end proc;

F3 := proc (rlist, deltalist) local product, i; product := 1; for i to 8 do product := product*deltalist[i]^rlist[i] end do; if ceil(sqrt(product)) = sqrt(product) then return true else return false end if end proc;

myProc40:=proc(deltalist) local r1, r2, r4, r5, r8, r10, r20, r40,rlist: for r1 from -1 to 3 do for r2 from -1 to 3 do for r4 from -1 to 3 do for r5 from -1 to 3 do for r8 from -1 to 3 do for r10 from -1 to 3 do for r20 from -1 to 3 do for r40 from -1 to 3 do rlist:=[r1,r2,r4,r5,r8,r10,r20,r40]: if (F1(rlist, deltalist) = true) then if(F2(rlist,deltalist)=true ) then if (F3(rlist, deltalist) = true) then if ((gcd(1,1)^(2)*r1)/(1)+(gcd(1,2)^(2)*r2)/(2)+(gcd(1,4)^(2)*r4)/(4)+(gcd(1,5)^(2)*r5)/(5)+(gcd(1,8)^(2)*r8)/(8)+(gcd(1,10)^(2)*r10)/(10)+(gcd(1,20)^(2)*r20)/(20)+(gcd(1,40)^(2)*r40)/(40)>0) and ((gcd(2,1)^(2)*r1)/(1)+(gcd(2,2)^(2)*r2)/(2)+(gcd(2,4)^(2)*r4)/(4)+(gcd(2,5)^(2)*r5)/(5)+(gcd(2,8)^(2)*r8)/(8)+(gcd(2,10)^(2)*r10)/(10)+(gcd(2,20)^(2)*r20)/(20)+(gcd(2,40)^(2)*r40)/(40)>0) and ((gcd(4,1)^(2)*r1)/(1)+(gcd(4,2)^(2)*r2)/(2)+(gcd(4,4)^(2)*r4)/(4)+(gcd(4,5)^(2)*r5)/(5)+(gcd(4,8)^(2)*r8)/(8)+(gcd(4,10)^(2)*r10)/(10)+(gcd(4,20)^(2)*r20)/(20)+(gcd(4,40)^(2)*r40)/(40)>0) and ((gcd(5,1)^(2)*r1)/(1)+(gcd(5,2)^(2)*r2)/(2)+(gcd(5,4)^(2)*r4)/(4)+(gcd(5,5)^(2)*r5)/(5)+(gcd(5,8)^(2)*r8)/(8)+(gcd(5,10)^(2)*r10)/(10)+(gcd(5,20)^(2)*r20)/(20)+(gcd(5,40)^(2)*r40)/(40)>0) and ((gcd(8,1)^(2)*r1)/(1)+(gcd(8,2)^(2)*r2)/(2)+(gcd(8,4)^(2)*r4)/(4)+(gcd(8,5)^(2)*r5)/(5)+(gcd(8,8)^(2)*r8)/(8)+(gcd(8,10)^(2)*r10)/(10)+(gcd(8,20)^(2)*r20)/(20)+(gcd(8,40)^(2)*r40)/(40)>0) and ((gcd(10,1)^(2)*r1)/(1)+(gcd(10,2)^(2)*r2)/(2)+(gcd(10,4)^(2)*r4)/(4)+(gcd(10,5)^(2)*r5)/(5)+(gcd(10,8)^(2)*r8)/(8)+(gcd(10,10)^(2)*r10)/(10)+(gcd(10,20)^(2)*r20)/(20)+(gcd(10,40)^(2)*r40)/(40)>0) and ((gcd(20,1)^(2)*r1)/(1)+(gcd(20,2)^(2)*r2)/(2)+(gcd(20,4)^(2)*r4)/(4)+(gcd(20,5)^(2)*r5)/(5)+(gcd(20,8)^(2)*r8)/(8)+(gcd(20,10)^(2)*r10)/(10)+(gcd(20,20)^(2)*r20)/(20)+(gcd(20,40)^(2)*r40)/(40)>0) and ((gcd(40,1)^(2)*r1)/(1)+(gcd(40,2)^(2)*r2)/(2)+(gcd(40,4)^(2)*r4)/(4)+(gcd(40,5)^(2)*r5)/(5)+(gcd(40,8)^(2)*r8)/(8)+(gcd(40,10)^(2)*r10)/(10)+(gcd(40,20)^(2)*r20)/(20)+(gcd(40,40)^(2)*r40)/(40)>0 ) then (print(`f(q) is in Sk with the following r values`,rlist)) end if: end if: end if: end if: end do: end do: end do: end do: end do: end do: end do: end do: end proc;

How can I find interesting Math apps written by Maple ?

Good morning.

I am working on engineering drawing project. I request your kind suggestions for

the above cited subject.

With thanks & Regards

M.Anand

Assistant Professor in Mathematics

SR International Institute of Technology,

Hyderabad, Andhra Pradesh, INDIA.

Dear all,

I tried to use pdsolve to solve the parabolic pde but get the unexpected answer:

Is it the PDESolStruc or the other structure? Where can I find the description about this kind of structure.

Thanks.