Here is ODE

restart:
with(plots):
Digits:=35:

ini1:=D(x)(0)=0,x(0)=1:
dsys:=diff(x(t),t,t)+(x(t)-2)*diff(x(t),t)+5*x(t)=0;
dsol1 :=dsolve({dsys,ini1},numeric,abserr=1e-9, relerr=1e-8,maxfun=0);
plots:-odeplot(dsol1,[[t,x(t)]],0..20,axes=boxed,color=black,linestyle=1,tickmarks=[6, 6],axes=boxed,titlefont=[SYMBOL,12]);

1-Why when i run for long time>1.5 give me error

2- how to plot phase plot of x'(t) against x(t)

Any comments will be helpful

I am a new user with Maple, and was using it as a documentation. But, can't fully see the file created a day before. 

The file opens but most of the content is gone and gives the error message.

There were problems during the loading process, Your worksheet may become incomplete

Googled a bit yet couldn't solve it :/ 

Is there any way to fix this?

Why_Mcausal_not_helping.mw

In plots made with 'complexplot3d', Maple uses by default a color wheel for the argument of complex numbers in which positive numbers are painted cyan and negative numbers are red. Is there a way to change this to the other common convention (i.e. cyan negative and red positive numbers)?

Any help would be really appreciated, as it's not convenient to have graphs made with different conventions in the same document and I wouldn't want to remake all the ones I already have.

I am trying to use Maple to discretize a model by solving an integral analytically. In my textbook the problem is solved by using Maple and is according to them "These calculations are quite straightforward to compute with Maple".

In my textbook there is an example where the non-linear system with state vector x(t) = [x1(t), x2(t), v(t), h(t), w(t)]' is described as

dx/dt=[v*cos(h), v*sin(h), 0, w, 0]'=a(x(t)).

To discretize this model the sampling formula x(t+T) = x(t) + int(a(x(tau)), tau=t..t+T) is used

Firstly, we can integrate the expressions row by row, the first row would then be

x1(t+T)=x1(t)+int(v(tau)*cos(h(tau)), tau=t..t+T).

The result when the sampling formula is applied to the first row in the example is

x1(t+T)=x1(t)+2v(t)/w(t)*sin(w(t)T/2)*cos(h(t)+w(t)T/2)

I have tried using int() and dsolve() but have only managed to get results that involve integrals. I would appreciate if someone more experienced could help me with this and maybe shed some light on if it actually is possible to do this?

I want to reference the previous equation/expression which is not displayed (':')in my worksheet. I allready know the '%' sign, but this references the previous equation/expression which was executed . By previous I mean the result (which is not displayed) in the previous line.

As I do not want the previous equation to be displayed I also cannot use the equation lable (CTRL+L).

Example

x:=a=b+1:

solve(previous,{b});

Thank you for your help.

I'm new here, so I'm not totally sure this is the right place to ask this. I apologize if it isn't, please let me know in that case.

My problem is that Maple won't recognize the built-in command 'complexplot3d'. For example, typing:

complexplot3d(z^2, z = -1-I .. 1+I)

doesn't do anything, and it's displayed again in blue as if it was not a command.

Any kind of help would be extremely helpful, as I have no clue of what's going on. Thanks in advance!

Hi everyone,

I'm kinda new here, and I really hope you guys can help me through this. In my new case study, after some revision, i thought i might be trying to implement a shooting method. I tried my best to make it work/understand but i couldn't get to any result.

So, as attached (i re-do PV Satya Naraya's paper first to be more understand but .....)

Here is my questions and the worksheet:

1) really stuck in mind - what is the purpose of shooting method for some related study?

2) what is the meaning of error .............'use midpoint method intead" 

3) Worksheet - 1MASS_JEFF_SATYA_on_Beta.mw

Thanks in advanced. Really hope that someone can help/teach me how to solve the boundary value problem by shooting method. 

Download 1MASS_JEFF_SATYA_on_Beta.mw

Good morning everybody


I know this question has already been widely discussed, for example in
http://www.mapleprimes.com/questions/149585-How-To-Order-Legend-Of-Multiple-Plots

I used the answer Kitonum then gave because I have basically the same kind of problem.
As an illustration, here is a sketch of my coding :

N := 3:
for k from 1 to N do
   ...
   MyPlot||k := PLOT(CURVES(....)):
   ...
end do:
plots:-display(seq(MyPlot||k, k=1..N));

The only difference is that I use PLOT instead of plot ... so I have thought that using LEGEND instead of legend would give me the desired result.
But I don't understand how to use LEGEND and how to place the legend in the correct location.

I will appreciate any answer,
Thanks in advance

Here, I attached my maple code. I need to find root. I am using fsolve. But I am not geting the root. Please any one help me... to find the root.

Download root.mw

Hello

Any idea about the summation of Fibonacci sequence

Fibonacci.mw

Best regards

Is there a way to force the branch choice with the LambertW?

If I turn on all _EnvAllSolutions:=true:

I get a placeholder for the branch. Unfortunately the name of this placeholder changes every time I re-evaluate.

Is there a way to force this to take a certain value?

Regards.

Hello, My problem is as following:

I have tried 2 options for solving the problem below, trying to plot the behaviour of a system to a predetermined function.

First I tried to use dsolve as usual:

restart; with(plots); C := setcolors(); with(LinearAlgebra);
eq1 := Force = Mass*(diff(y(t), `$`(t, 2)));
formula1 := 2.6*BodyWeight*abs(sin(4*Pi*t));
2.6 BodyWeight |sin(4 Pi t)|
BodyWeight := 80*9.81;
plot(formula1, t = 0 .. 2);

eq2 := formula1-SpringConstant*(diff(y(t), t)) = Mass*(diff(y(t), `$`(t, 2)));
/ d \ / d /
2040.480 |sin(4 Pi t)| - SpringConstant |--- y(t)| = Mass |--- |
\ dt / \ dt \

d \\
--- y(t)||
dt //
Mass := .200;
Springt := 200;
200
SpringConstant := Youngsmodulus*Surface/DeltaLength;
DeltaLength := 0.2e-1-y(t);
Surface := .15;
Youngsmodulus := 1600*10^6-20*t^2;
eq2;
/ 2 \ / d \
0.15 \-20 t + 1600000000/ |--- y(t)|
\ dt /
2040.480 |sin(4 Pi t)| - ------------------------------------- =
0.02 - y(t)

/ d / d \\
0.200 |--- |--- y(t)||
\ dt \ dt //

incs := y(0) = 0, (D(y))(0) = 0;
eq4 := dsolve({eq2, incs});
Warning: System is inconsistent

Second, I tried using a numerical solving, with maxfun.

restart; with(plots); C := setcolors(); with(LinearAlgebra);
eq1 := Force = Mass*(diff(y(t), `$`(t, 2)));
formula1 := 2.6*BodyWeight*abs(sin(4*Pi*t));
2.6 BodyWeight |sin(4 Pi t)|
BodyWeight := 80*9.81;
plot(formula1, t = 0 .. 2);

eq2 := formula1-SpringConstant*(diff(y(t), t)) = Mass*(diff(y(t), `$`(t, 2)));
/ d \ / d /
2040.480 |sin(4 Pi t)| - SpringConstant |--- y(t)| = Mass |--- |
\ dt / \ dt \

d \\
--- y(t)||
dt //
Mass := .200;
Springt := 200;
200
SpringConstant := Youngsmodulus*Surface/DeltaLength;
DeltaLength := 0.2e-1-y(t);
Surface := .15;
Youngsmodulus := 1600*10^6-20*t^2;
eq2;
/ 2 \ / d \
0.15 \-20 t + 1600000000/ |--- y(t)|
\ dt /
2040.480 |sin(4 Pi t)| - ------------------------------------- =
0.02 - y(t)

/ d / d \\
0.200 |--- |--- y(t)||
\ dt \ dt //

incs := y(0) = 0, (D(y))(0) = 0;
eq4 := dsolve({eq2, incs}, y(t), type = numeric, output = listprocedure, maxfun = 10^7);
[
[t = proc(t) ... end;, y(t) = proc(t) ... end;,
[

d ]
--- y(t) = proc(t) ... end;]
dt ]

test := rhs(eq4[2]);
proc(t) ... end;

This one does plot, but no further than 0.2*10^-6. I have tried compiling the data, but this has not worked yet.

Does anyone know a way to work around such a problem. Is it possible to plot the equation using a for loop? If yes, how?

How do I use Maple to pull the propane price from www.fuelsonline.ca ?

If I use HTTP[Get]("http://www.fuelsonline.ca")

I only get            301,""

Any help?

Hello everybody.

I have a function:

f(x,y)=GAMMA(y, -ln(x))/GAMMA(y)

seq(sum(f(x, y), y = 0 .. 1), x = 0 .. 5)

and I got a error message:

Error, (in ln) numeric exception: division by zero ??
This is normal behavior in seq function or Bug?

but  when I'm first calculate the sum sol := sum(f(x, y), y = 0 .. 1) -> x,

and evalf([seq(sol, x = 0 .. 5)]) ->[0., 1., 2., 3., 4., 5.] works fine.

Seq-division_by_zero.mw

Mariusz Iwaniuk

My old harddisk recently died and I am currently using a new one. I still have the license code for Maple 2016. Is it still possible for me to install Maple 2016 or 1 license = 1 installation?