Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hello,

I am trying to solve analytically a simple system of partial differential equations with boundary conditions and I am not able to do it. Even in the very simple case of

pdsolve([diff(u(x, y, t), y, y) = 0, diff(p(x, y, t), y) = 0, u(x, 0, t) = 1, (D[2](u))(x, 1, t) = 0, p(x, 1, t) = 2], [p(x, y, t), u(x, y, t)]);

I don't get any answer.  However if I remove the boundary conditions I get the right answer

pdsolve([diff(u(x, y, t), y, y) = 0, diff(p(x, y, t), y) = 0], [{p(x, y, t), u(x, y, t)}]);
 {p(x, y, t) = _F3(x, t), u(x, y, t) = _F1(x, t) y + _F2(x, t)}

Can maple 2015 solve analytically systems of partial differential equations with boundary conditions? I have not been able to find any example anywhere.

Thanks a lot for your help.

Javier

Hi MaplePrimes,

As an amataeur with this computer tool, I want to know the arrow notation.

For example " l -> 8*l ".

a_quandry_MaplePrimes.mw

I'm sure this easy question is okay.

Regards,

Matt

 

Respected members!

I downloaded this file because I've to study the geodesics over the cone, the sphere and the cylinder (and in general on a Riemannian manifold). But when I modify the equation, putting one of that I'm interested to, the file doesn't work (for example, it doesn't recognize the "assign" command). Could you help me, please?

 

http://www.maplesoft.com/applications/download.aspx?SF=34940/199536\GeodesicsSurface.pdf

Best,

Marzio

Respected member!

Please help me in finding the solution of this problem....
 

NULL

 

 

NULL

>   

``

NULL

restart

with(RealDomain):

r := .2:

k := 5;

5

(1)

BCSforNum1 := u(0) = 0, (D(u))(0) = 1+beta*(((D@@2)(u))(0)-(D(u))(0)*RealDomain:-`^`(k, -1)), (D(u))(m) = 0, ((D@@2)(u))(m) = 0;

u(0) = 0, (D(u))(0) = 1+.2*((D@@2)(u))(0)-0.4000000000e-1*(D(u))(0), (D(u))(6) = 0, ((D@@2)(u))(6) = 0

 

v(0) = 1, v(6) = 0

(2)

numsol1 := dsolve({BCSforNum1, BCSforNum2, ODEforNum1, ODEforNum2}, numeric, output = listprocedure)

Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging

 

``


 

Download mplprimes.mw

Dear community, 

I'm new to maple and was wondering if you could help me out.

I have this curve where I want to make a line that goes from x=0.5 up to its value on the curve in this case 1.60 and then all the way to the y-axis so there is an area under the curve which I can color if that's even possible?

I have the following in maple:

k := 2.5;
                              2.5
Ca0 := 1;
                               1
v := 20;
                               20
Ca := Ca0*(1-x);
                             1 - x
Fa0 := Ca0*v;
                               20
Cb := Ca0*x;
                               x
ra := k*Ca*Cb;
                         2.5 (1 - x) x
plot(1/ra, x = 0 .. 1);
 

thank you for your help

Best Regards

Saad

I am curious whether anyone here can come up with a way to simplify the expression x1 to 15*Pi/32 in fewer exact, symbolic steps. The following was performed in Maple 2016.2 for Linux.

restart;

x1 := arcsin(1/2*(2+(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2));

arcsin((1/2)*(2+(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2))

x2 := evalc(convert(x1,expln));

arctan((2+(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2)/(2-(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2))

x3 := convert(x2, expln);

((1/2)*I)*(ln(1-I*(2+(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2)/(2-(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2))-ln(1+I*(2+(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2)/(2-(2+(2+2^(1/2))^(1/2))^(1/2))^(1/2)))

# non-Pro wolframalpha can simplify x3 to 15*Pi/32 (but not x2 or x1).
#

x4 := combine(x3);

((1/2)*I)*ln(-(I*2^(1/2)*((2+2^(1/2))*(2+(2+2^(1/2))^(1/2)))^(1/2)+I*(2*2^(1/2)+4)^(1/2)+I*2^(1/2)+(-1+I))/(I*2^(1/2)*((2+2^(1/2))*(2+(2+2^(1/2))^(1/2)))^(1/2)+I*(2*2^(1/2)+4)^(1/2)+I*2^(1/2)+1+I))

x5 := simplify(x4);

((1/2)*I)*(-ln(2)+ln(-(2+(2+2^(1/2))^(1/2))^(1/2)*(I*2^(1/2)*(2+2^(1/2))^(1/2)-I*2^(1/2)+1-I)))

x6 := expand(x5);

-((1/2)*I)*ln(2)+((1/4)*I)*ln(2+(2+2^(1/2))^(1/2))+((1/2)*I)*ln(-I*2^(1/2)*(2+2^(1/2))^(1/2)+I*2^(1/2)+(-1+I))

x7 := combine(x6);

-((1/4)*I)*(ln(-(1/2)*(2+2^(1/2))^(1/2)*(I*2^(1/2)+(-1-I)))+(2*I)*Pi)

simplify(x7,constant);

(15/32)*Pi

# It's a pity that last step worked while this next is inadequate.
simplify(x7);

-((1/4)*I)*ln(-(2+2^(1/2))^(1/2)*(I*2^(1/2)+(-1-I)))+((1/4)*I)*ln(2)+(1/2)*Pi

# Another way, using x7
simplify(evalc(x7));

(15/32)*Pi

# Another way, using x7
simplify(combine(expand(x7)));

(15/32)*Pi

 

Download simplify_example.mw

I am trying to solve system linear partial differential equations using command "pdsolve". I am surprised to see that the solution given by this command is not satisfying the system, instead, an additional constraint is obtained for an arbitrary function, is there something about "pdsolve" I am missing? 


 

with(PDEtools):

DepVars := [f(x, y, t, u)]

[f(x, y, t, u)]

(1)

Sys := {diff(f(x, y, t, u), u, t)-(diff(f(x, y, t, u), x, y)) = 0, diff(f(x, y, t, u), u, u) = 0, diff(f(x, y, t, u), u, y) = 0, diff(f(x, y, t, u), x, u) = 0, diff(f(x, y, t, u), x, x) = 0, diff(f(x, y, t, u), y, y, y) = 0}

{diff(diff(f(x, y, t, u), t), u)-(diff(diff(f(x, y, t, u), x), y)) = 0, diff(diff(diff(f(x, y, t, u), y), y), y) = 0, diff(diff(f(x, y, t, u), u), u) = 0, diff(diff(f(x, y, t, u), u), x) = 0, diff(diff(f(x, y, t, u), u), y) = 0, diff(diff(f(x, y, t, u), x), x) = 0}

(2)

pdsolve(Sys)

{f(x, y, t, u) = (_F3(t)*y+_F4(t))*x+(_F3(t)+_C1)*u+(1/2)*_F7(t)*y^2+_F8(t)*y+_F9(t)}

(3)

f := proc (x, y, t, u) options operator, arrow; (_F3(t)*y+_F4(t))*x+(_F3(t)+_C1)*u+(1/2)*_F7(t)*y^2+_F8(t)*y+_F9(t) end proc

proc (x, y, t, u) options operator, arrow; (_F3(t)*y+_F4(t))*x+(_F3(t)+_C1)*u+(1/2)*_F7(t)*y^2+_F8(t)*y+_F9(t) end proc

(4)

Sys

{0 = 0, diff(_F3(t), t)-_F3(t) = 0}

(5)

``


 

Download pdsolve_command.mw

In the recent years much software has undergone a change towards allowing for better sharing of documents. As is the case with other software as well, the users are no longer mainly single persons sitting in a dark corner doing their own stuff. Luckily Maplesoft has taken an important step in that direction too by introducing MapleCloud some years ago. This means that it is now possible quite easily to discuss calculations done in Maple in the classroom. One student uploads and the Teacher can find the document seconds later on his own computer connected to a Projector and show the student's solutions for the other  students in the classroom. That's indeed great! Maple is however lacking in one important aspect: It's Graphics User Interface (GUI) is not completely ready to for that challenge! I noticed that quite recently when the entire teaching staff received new netbooks: 14 inch Lenovo Yoga X1 with a resolution of 2560 x 1440 pixels. From factory defaults text zoom was set to 200%. Without it, text would be too small in all applications used on the computer. The Microsoft Office package and most other software has adapted to this new situation dealing with high variation in the users screen resolutions, but not Maplesoft:

  1. Plots and Images inserted become very small
  2. Open File dialogs and the like contain shortened text for folder names ... (you actually have to guess what the folders are)
  3. Help menus are cluttered up and difficult to read.

I show screen images of all three types below.

I know it is possible to make plots larger by using the option size, but since it relies on pixels it doesn't work when documents are shared between students and teachers. You cannot expect the receiving student/teacher to make a lot of changes in the document just to be able to read it. It will completely destroy the workflow!

Why doesn't Maplesoft allow for letting documents display proportionally on the users computer like so many other programs do? Why do it need to be in pixels? If it is possible to make it proportional, it would also solve another issue: Making prints (to a printer or to pdf) look more like they do on the screen than is the case at present.

I really hope Maplesoft will address this GUI challenge, because I am sure the issue will pile up quite rapidly. Due to higher costs, most laptops/netbooks among students don't have that high resolution compared to computer dimensions at the moment, but we already have received a few remarks from students owning such computers. Very soon those highend solution computers will dive into the consumer market and become very common.

I have mentioned this important GUI issue in the beta-testing group, but I don't think those groups really are adapted to discussions, more bug fixes. Therefore I have made this Post in the hope that some Maple users and some chief developers will comment on it!
     

Now I have criticized the Maple GUI, I also feel urged to tell in what departments I think Maple really excels:

  1. The Document-structure is great. One can produce good looking documents containing 'written math' (inactive math) and/or 'calculated math'. All-in-one! Other competting software does need one to handle things separatly.
  2. Sections and subsections. We have actually started using Maple to create documents containing entire chapters or surveys of mathematics or physics subjects, helping students to get a better overview. I am pretty sure the Workbook tool also will help here.
  3. Calculations are all connected. One can recalculate the document or parts of it, eventually using new parameters. Using Maple for performing matematical experiments. Mathematical experiments is a method entering more into the different mathematics curriculums.
  4. MapleCloud. Easy sharing of documents among students and teachers.
  5. Interactive possibilities through the Explore command and other commands. Math Apps as well.
  6. Besides that mathematical symbols can be accessed from the keyboard, they can also be accessed from palettes by less experinced users.  
  7. Good choice by Maple to let the user globally decide the size text and math is displayed in Maple - set globally in the menu Tools < Options.
  8. Maple can handle units in Physics
  9. Maple has World-Class capabilities. If you have a mathematical problem, Maple can probably handle it. You just need to figure out how.
  10. etc.

 

Small plots:

 

Shortened dialog text:

 

Cluttered help menus:

 

Regards,

Erik

 

Good day sirs,

I am trying to plot graphs on stream function but its given me a lot of multiple error using my codes. Anyone with useful information should please share. 

Below is the code.

Thanks

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/Test.mw .
 

Download Test.mw

 

HI Maple primes.  We try to make sense of 'rsolve' in the Maple world.  What is command for source code?

 

Regards,

Matt

 

Can't understand what's wrond. This text from my academic books but it doesn't work on practice. Help please

 

plot3d(polygons([[0, 0, 0], [1, 0, 0], [1, 0, 0], [0, 1, 0]], [[0, 0, 0], [0, 1, 0], [0, 1, 1], [0, 0, 1]], [[1, 0, 0], [1, 1, 0], [1, 1, 1], [1, 0, 1]], [[0, 0, 0], [1, 0, 0], [1, 0, 1], [0, 0, 1]], [[0, 1, 0], [1, 1, 0], [1, 1, 1], [0, 1, 1]], [[0, 0, 1], [1, 0, 1], [1, 1, 1], [0, 1, 1]]), light(0, 0, 0.0, 0.7, 0.0), light(100, 45, 0.7, 0.0, 0.0), light(100, -45, 0.0, 0.0, 0.7), ambientlight(.4, .4, .4), title(cube), style(patch), color(zhue));

Error, (in plot3d) bad range arguments: light(0, 0, 0., .7, 0.), light(100, 45, .7, 0., 0.)
 

Hi Mapleprimes,

We know that '' rsolve '' is a recurrence equation solver.  It is more than an expression simplifier.

Congratulations to the Maple computer algebra team for creating such a great computer tool.  simply want to know more.

rsolve_on_May_16_2017.pdf

Surely there are many steps to determine the values to place.

Regards,

Matt

 

I recently encontered a very strange result.

Lets define the procedure:

Fg := proc(x0,y0)
if (x0>=0)and(x0<=3) and (y0<=x0+2) and (y0>=x0-1) and (y0>=0) and (y0 <=3) then
return y0*(3-y0)*x0*(3-x0)*(x0+2-y0)*(y0-x0+1);
else
return 0;
end if:
end proc:

The plot looks like needed:

plot3d('Fg'(x,y), x=0..3, y=0..3);

But integration returns weird result:

evalf(Int('Fg'(x,y), [x=0..1, y=0..2.1]));

7.888753239

evalf(Int('Fg'(x,y), [x=0..1, y=0..2.2]));

Error, (in evalf/int) when calling 'Fg'. Received: 'cannot determine if this expression is true or false: 0 <= x and x <= 3 and y <= x+2 and x-1 <= y and 0 <= y and y <= 3'

hi...i have a problem with pdsolve this equations?

please help me.

thanks

mt.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/mt.mw .
 

Download mt.mw

 

I have a expression p:=C*A+A, when i type this to maple, maple display into p:=A*C+A because commutative property of multiplication

but I dont want to do like that. How can I display into p:=C*A+A?

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