Maple 2018 Questions and Posts

These are Posts and Questions associated with the product, Maple 2018

Update

I am not sure what happened, but now after starting Maple, these PDE's no longer hang. Even though I tried them before number of times before posting to make sure.  This is strange. I do not know what happened.

Any way, there is no issue any more. These do not hang in version 319.

original post

Hello Maple experts.

FYI, I noticed some pde's are no longer solved (hang) after downloading latest physics package cloud version 319, when before when using version 301 these were solved.

version()
 User Interface: 1362973
         Kernel: 1362973
        Library: 1362973
                            1362973
Physics:-Version()
 "C:\Maple_updates\Physics_Updates_319.maple", 2019, March 3, 
    17:7 hours, version in the MapleCloud: 319, version installed in this 
    computer: the "Physics Updates" is not  installed.

Any idea why this happened? It is possible this is due to bug fix of course, but thought to point this out.

These PDE's were solved with Maple 2018.2.1 with Physics ver. 301 but not in ver. 319

#now not solved or hangs, before it was solved in 7 seconds
pde := diff(u(x, t), t) = (1/20)*(diff(u(x, t), x$2))+t;
bc := u(0, t) = 5, (u(1, t)+ eval( diff(u(x,t),x),x=1)) = 10;
ic:= u(x, 0) = -40*x^2/3+45*x/2+5;
pdsolve([pde, bc,ic], u(x, t));

#now it hangs, before it was solved in 0.2 seconds
pde :=  (A*y^2+B*x^2-a^2*B)*diff(w(x,y),x)+(C*y^2+2*B*x*y)*diff(w(x,y),y) = 0;
pdsolve(pde,w(x,y));

#now hangs when it was solved before in 5 seconds
pde := 2*diff(w(x,y),x)+((lambda+a-a*sin(lambda*x))*y^2 +lambda -a -a*sin(lambda*x))*diff(w(x,y),y) = 0;
pdsolve(pde,w(x,y));

#now hangs when it was solved before in 1.8 seconds
pde := diff(w(x,y),x)+((lambda+a*sin(lambda*x)^2)*y^2 + lambda -a +a*sin(lambda*x)^2)*diff(w(x,y),y) = 0;
pdsolve(pde,w(x,y));

Using windows 10.

 

How do I remove Array B from Array A? e.g.

A:=Array([1,2,3,4,5,6,7,8...1000]
B:=Array([3,6,9,12,15....])   assuming A contains all the elements of B.

to get [1,2,4,5,7,8,11....]

Also is it possible to do it in place?

.I am testing out the MutableSet command, There seems to be a problem with the number of emements that can be operated on. When N =100000 things are ok. When N=1000000 (or there abouts) the process doesn't terminate last line. Uorks ok for sets. Using Maple 2018.2 on Win10 64bit.


 

restart

N := 900000

900000

(1)

A := {seq(i^2, i = 1 .. N)}

B := {seq(A[i+1]-A[i], i = 1 .. nops(A)-1)}

``

``

C := MutableSet(seq(i^2, i = 1 .. N))

module MutableSet () local storage; global MutableSet; option object; end module

(2)

upperbound(C)

900000

(3)

MutableSet(seq(C[i+1]-C[i], i = 1 .. N-1))

``


 

Download Mutable_set_issue.mw

Hello every one,

My slideshow now contains a lot of animation sequences and take
a very long time to load and a large amount of physical memory (>20GB).

To reduce this size I have decided to convert these animations to GIF format.
Unfortunatly Maple/MaplePayer do not play GIF animations.

I decide to put URLs (image icons pointing to GIF files) in the document.
Now the GIF are play by a WEB browser (program to operate in fullscreen 
mode to minimize any disturbance in the audience with IE11).

Now the issue:
Using F11 to start the Slideshow, cliking the URL start the browser with the requested
animated GIF, that is fine, but now Maple/MaplePayer both auto-exit fullscreen
mode just after that click. The speaker (me) now need to manage the return to
fullscreen (F11) at the current slide while
thinking about what i have to
say next.

Is there any trick to prevent auto-exit from fulls-screen mode in this situation?

Thank you for your help

LL

 

Des suggestions de solutions? Merci.

A) a) Écrire une procédure qui produit une itération du calcul babylonien de la racine carrée d'un nombre positif k à partir     d'une première approximation x0 .

    Entrée: k , x0 .

    Sortie:  x1 = (x0+ k/x0)/2 .

b) En utilisant la procédure trouvée en a), en écrire une autre, qui prend en entrée un entier positif n en plus des entiers k   et x0 vus en a) et qui retourne en sortie n itérations du calcul babylonien de la racine carée de k.

 B)

Écrire une procédure récursive Maple qui prend en entrée deux nombres n et k et qui utilise l'identité (n k) = (n -1k)+(n-1 k-1) pour retourner en sortie le coefficient binomial (n k) , cette procédure ne doit pas utiliser la commande Maple binomial.

TRADUCTION:

Suggestions for solutions? Thank you.

A) a) Write a procedure that produces an iteration of the Babylonian calculus of the square root of a positive number k from a     first approximation x0.

    Input: k, x0.

   Output: x1 = (x0 + k / x0) / 2.

b) Using the procedure found in a), write another one, which takes as input a positive integer n in addition to the integers k and   x0 seen in a) and which returns in exit n iterations of the Babylonian calculation of the square root of k.

B) Write a Maple recursive procedure that takes as input two numbers n and k and uses the identity (n k) = (n-1 k)+ (n-1 k-1) to   return the binomial coefficient (n k), this procedure should not use the binomial Maple command.

Hi , how we can read the fractional differential equations in maple with out solving . I means just read and determine which is the order of fractional differential equations.

thanks

Hello everyone!

In previous versions of Maple (e.g. Maple 2016) it used to be possible to use scaletorange and colorscheme options together as in:

densityplot(sin(x+y), x = -1 .. 1, y = -1 .. 1, colorscheme = [black, red, yellow, white], scaletorange = -.5 .. .5);

But Maple 2018 returns an error:

Error, (in plots/densityplot) the scaletorange option cannot be used with the colorscheme option

Why is that and can one work around this error in any simple way?

  Y'a t-il des suggestion de résolution de ce qui suit? merci.

a) On pose F(-1,0) et F`(1,0) les foyers de l'ellipse E, on veut déterminer son équation implicite f(x,y)=0, 
    des points A(x,y) sur l’ellipse en utilisant la description bifocale et sans utiliser Maple.
  b) Utilisez la commande implicitplot de Maple et le résultat de a) pour tracer plusieurs ellipses sur
    le même graphe en variant la valeur de la constante C,(la somme des distances aux foyers F, F’ est
une constante qui est C).

Traduction:

  a) We put F (-1,0) and F` (1,0) the foci of the ellipse E, we want to determine its implicit equation f (x, y) = 0,
     A (x, y) points on the ellipse using the bifocal description and without using Maple.
  b) Use the command implicitplot of Maple and the result of a) to draw several ellipses on
     the same graph by varying the value of the constant C, ( FA +F'A = C ). 

     Give at the end a Maple procedure that generates this ellipse.

with(plottools):F := proc (N) local a, b, L; L := NULL; L := sort([op({seq(seq(a/b, a = 0 .. b), b = 1 .. N)})]); return L end proc; F(6);
            [   1  1  1  1  2  1  3  2  3  4  5   ]
            [0, -, -, -, -, -, -, -, -, -, -, -, 1]
            [   6  5  4  3  5  2  5  3  4  5  6   ]
Ford6 := proc (i) local d, k, n, r; k := i; n := numer(F(6)[k]); d := denom(F(6)[k]); r := (1/2)/d^2; return [n/d, r], r end proc; nops(F(6));
                               13
for i to 13 do C || i := Ford6(i) end do;

display(circle(C1), circle(C2), circle(C3), circle(C4), circle(C5), circle(C6), circle(C7), circle(C8), circle(C9), circle(C10), circle(C11), circle(C12), circle(C13), axes = normal, scaling = constrained, color = blue, size = [800, 800]);


Hello there,

I have created a MAPLE document in a slideshow format.

Is there a way to print a copy of my presentation with header and footer included and in a format that fits on letter format paper or pdf.

Thank you for your help.

LL

I have 2 questions here

1st I want to extend this set Ug3 := {1, 19, 23, 29} by repeatively subtracting 6 fron its elements. first pass should give

Ug3 := (Ug3-~ 6) union Ug3  Ug3 := {-5, 1, 13, 17, 19, 23, 29}

Now I dont want to add any elenments less than 6 so -5 need to go

Second pass produces

Ug3 := (Ug3-~ 6) union Ug3                Ug3 := {-11, -5, 1, 7, 11, 13, 17, 19, 23, 29}

Obiviously no elements less than 6 to be added on second pass either.

At this point there is no further elements that could be added to the set.

I am looking for an efficient method. I can use For loops and if then checks. The sets grow in length quickly. Repetition lengths are 6, 30 210, 2310,... I use sets because the numbers get ordered automaticially. Are sets efficient or should I use some form of table?
 

How I can perform integration by parts, with respect to the x[0..1],y[0..1],t 

PART.mw
 

restart

U := (1/2)*(E*(diff(u(x, y), x)-z*(diff(w(x, y), x, x))+(1/2)*(diff(w(x, y), x))^2)/(-upsilon^2+1)+E*upsilon*(diff(v(x, y), y)-z*(diff(w(x, y), y, y))+(1/2)*(diff(w(x, y), y))^2)/(-upsilon^2+1))*(diff(u(x, y), x)-z*(diff(w(x, y), x, x))+(1/2)*(diff(w(x, y), x))^2)+(1/2)*(E*upsilon*(diff(u(x, y), x)-z*(diff(w(x, y), x, x))+(1/2)*(diff(w(x, y), x))^2)/(-upsilon^2+1)+E*(diff(v(x, y), y)-z*(diff(w(x, y), y, y))+(1/2)*(diff(w(x, y), y))^2)/(-upsilon^2+1))*(diff(v(x, y), y)-z*(diff(w(x, y), y, y))+(1/2)*(diff(w(x, y), y))^2)+E*(1-upsilon)*((1/2)*(diff(v(x, y), x))-z*(diff(w(x, y), x, y))+(1/2)*(diff(u(x, y), y))+(1/2)*(diff(w(x, y), x))*(diff(w(x, y), y)))^2/(-upsilon^2+1)+2*E*l^2*(diff(w(x, y), x, y))^2/(2+2*upsilon)+2*E*l^2*(-(1/2)*(diff(w(x, y), x, x))+(1/2)*(diff(w(x, y), y, y)))^2/(2+2*upsilon)+2*E*l^2*((1/4)*(diff(v(x, y), x, x))-(1/4)*(diff(u(x, y), x, y)))^2/(2+2*upsilon)+2*E*l^2*((1/4)*(diff(v(x, y), x, y))-(1/4)*(diff(u(x, y), y, y)))^2/(2+2*upsilon)

with(IntegrationTools)

``

``


 

Download PART.mw

 

 
 1)  Copy/paste problem .
 
 Looks like Maple is not able to copy/paste the output
 from a summation command . Look at my example .
 I have to use the  " lprint " command .
2)   Mysterious small box character .
 
 Suppose I want to edit a command . I want to replace a character with a left bracket
 (or right bracket or left accolade but strangely not the right accolade).
 I put the cursor on the character and type the left bracket (or right...) .
 The left bracket ( or right ...)  is inserted . Now when I try to delete the character,
 a small box appear . The  character I am trying to delete is shifting to the right .
  Like  I said , just a little annoying .
 
3)  Open file problem .
 
 The first file I open in Maple with the  ctrl-o command , the "open file window" appears in
  the center of the screen . All the others files I am opening , the "open file window"  show up
  in the bottom left corner , top center or top right corner ... randomly .
  Very annoying on a 27" screen . For this last one ,I am not shure  if it is a Maple 2018 problem
   or a Windows 10 64 bits problem . I have few programs in my computer .
  When I use Microsoft Paint or Wordpad ,I don't see this problem .
 
  I don't know if somebody else can confirm those annoying things . If I am not the only one
  then I am hoping the next updates or versions will fix that .
 
    Thanks !
 

with(plottools):with(plots): display(seq(seq(display(polygon([[i,j],[i,j+1],[i+1,j+1],[i+1,j]], color=`if``((j)::odd,ColorTools:-Color=magenta))), textplot([1+.5,j+.5,fprintf("%d",i*j)])),i=1..10), j=1..10),axes=none);

Hello Maple experts:

Using Maple 2018.2.1 on windows, with Physics package version 301.

There is some strange issue in parsing somewhere.  This works

r:='r'; u:='u'; t:='t';theta:='theta';k:='k';
k:=1/25;
pde := diff(u(r,theta,t),t)=k*(diff(u(r,theta,t),r$2) + 1/r*diff(u(r,theta,t),r)+1/r^2*diff(u(r,theta,t),theta$2));
bc1:= eval(diff(u(r,theta,t),r),r=1)=0;
bc2:= u(r,0,t)=0, u(r,Pi,t)=0;
ic := u(r,theta,0)=(r-1/3*r^3)*sin(theta);
sol:=pdsolve([pde, bc1, bc2, ic], u(r, theta, t),HINT = boundedseries(r = [0]));

No problem with the above, pdsolve gives solution. Now if I change k from 1/25 to 1, it gives parsing error in map

k:=1;
pde := diff(u(r,theta,t),t)=k*(diff(u(r,theta,t),r$2) + 1/r*diff(u(r,theta,t),r)+1/r^2*diff(u(r,theta,t),theta$2));
bc1:= eval(diff(u(r,theta,t),r),r=1)=0; 
bc2:= u(r,0,t)=0, u(r,Pi,t)=0;
ic  := u(r,theta,0)=(r-1/3*r^3)*sin(theta);
sol := pdsolve([pde, bc1, bc2, ic], u(r, theta, t),HINT = boundedseries(r = [0]));

Error, (in assuming) invalid input: map expects 2 or more arguments, but received 1

any K value less than one works. 

Now I change K from 1 to 2, the error goes away. But no solution. Which is OK.

Why does the map error shows up when k=1 only? Same error shows up if K is missing all togother, as in

r:='r'; u:='u'; t:='t';theta:='theta';k:='k';
pde := diff(u(r,theta,t),t)=diff(u(r,theta,t),r$2) + 1/r*diff(u(r,theta,t),r)+1/r^2*diff(u(r,theta,t),theta$2);
bc1:= eval(diff(u(r,theta,t),r),r=1)=0; 
bc2:= u(r,0,t)=0, u(r,Pi,t)=0;
ic  := u(r,theta,0)=(r-1/3*r^3)*sin(theta);
sol := pdsolve([pde, bc1, bc2, ic], u(r, theta, t),HINT = boundedseries(r = [0]));

Error, (in assuming) invalid input: map expects 2 or more arguments, but received 1

 

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