Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

why does Maple say that timelimit got one argument when doing

timelimit(30,solve(x^2+a=0,x) assuming a>0)

There is clearly 2 arguments in the above, The first is 30 and the second argument is solve(x^2+a=0,x) assuming a>0

I know the workaround is to add [ ] around solve(). 

timelimit(30, [solve(x^2+a=0,x) assuming a>0])

Maple 2020.1 windows

My problem is: factoring G from c4s1 results in different value in c4s2. Why?

wfn := 12; win := 5; wun := 90; zd := .8; xd := 80; xfd := -500; xid := 12; x0d := 66; lamf := 11; lamu := 44; lami := .99; G := 6.7777; kxui := 10; kxif := 33; 
cg3 := evalf(-kxui*cos(wun*zd)*exp(lamu*(xid-x0d))*(exp(-2*lamf*xfd)*(kxif*lami-lamf)+kxif*lami+lamf)/(2*cos(win*zd)*(cosh(lami*xid)*(kxif*kxui*lami*lamu*(1+exp(-2*lamf*xfd))+lamf*lami*(1-exp(-2*lamf*xfd)))+sinh(lami*xid)*(kxif*lami^2*(1+exp(-2*lamf*xfd))+kxui*lamf*lamu*(1-exp(-2*lamf*xfd))))));
c4s1 := evalf(   exp(lami*xid)*cos(win*zd)*exp(lamu*x0d)*cg3*G*kxui*lamu+exp(lami*xid)*cos(win*zd)*exp(lamu*x0d)*cg3*G*lami+G*kxui*cos(wun*zd)*exp(lamu*xid)); 
c4s2 := evalf(G*(exp(lami*xid)*cos(win*zd)*exp(lamu*x0d)*cg3  *kxui*lamu+exp(lami*xid)*cos(win*zd)*exp(lamu*x0d)*cg3  *lami+  kxui*cos(wun*zd)*exp(lamu*xid)));
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Dear maple users @acer @Carl Love @Kitonum @Preben Alsholm @dharr @tomleslie

Greeting.

I have solved some PDEs in analytically and numerically.

But the numerical and analytical results are not matching.

I hope there is some problem with an analytical solution, especially in the first order and second-order boundary conditions.

Both the codes have enclosed here, waiting for a reply.

AN.mw

NUM.mw

Note: The PDEs are performed in the Maple 18 version. 

When compiling an analytical solution, in clarify expression click the remember table assignment.

 

Hi,

How to use animate command in the situation of  Fractals (LSystemExamples), and  how to add plot options (color,..)?

Thanks for your help

FractalesAnim.mw

I am interested in the AC circuits which control electric motor performance.

I have installed the Syrup package, written by Joseph Riel, from the Application Centre but it seems to draw and solve only DC powered circuits.

Does Syrup have AC circuit capability?

If not, is there any available package written in Maple which can draw and analyse AC circuits, preferably one in which the circuit can be constructed by clicking circuit elements in an palette and dragging them to a canvas?

Finally, if there is no such Maple package, can you point me to an equivalent, free package which is downloadable from the internet? 

I guess this command got missed?

with(ColorTools)

?ColorString

 

 

The solver seems to have a problem with some sets of boundary conditions. (See attached worksheet.)

Is there a way to get this numerical solution?
 

BC_test.mw

Dear colleagues,

 

how can i plot streamlines and isothermes and also 3D graphes of Nussult number and skin friction coefficient for boundary layer flow problem with Maple? 

Regards

Berham.

MagBVP.mw

MagBVP.docx

maple_event_test.mw

I want to catch the trigger time t[i]

[differentiation of f and greek letter xi in bracket]

Hello,

I was wondering if it is possible to write a 1st order differential equation in differential form?

So,

Instead of writing the diff eq in 

ode:=diff(y(x),x)=x^2+x*y(x)

is it possible to to write something like

ode: -(x^2+x*y(x))*D(x)+ (1)*D(y(x))=0

?

I've asked about this 5 years ago

 

https://www.mapleprimes.com/questions/203628-Maple-2015-No-Longer-Autoscroll-As

And according to the reply there at the time, this is supposed to have been fixed in Maple 2015.1:

It appears that the scrolling issue has been fixed in the next version of Maple

But ever since then, whenever I use Maple, the worksheet do not auto-scroll as the program runs and prints outout to the screen. I have to keep using the mouse to move the bar down to see the latest prints.

Not only that, the bar itself (on the right side) shrinks in size as more outpout is printed.

It becomes smaller and smaller with time, and becomes very hard to grab it with the mouse since it become so thin.  Once all the output is deleted, the bar become long again.

So I think there is an option to enable autoscrolling somewhere.

But I am not able to find it. I looked at options, display, general and interface and see nothing there to turn it on.

Sometimes I get the feeling that the folks at Maplesoft do not use Maple interface the way we users use it, becuase this is such a basic interface problem and any one who uses Maple interface for more than one day must see these problems all the time.

So how come these are still not fixed?  Here is a screen shot showing the bar on the right after long print out, and showing how it was before.

I use only worksheet mode, not document mode. On windows 10.

 

 

 

 

Trying to get a curve of two data points but the graph is not a curve.

with(Statistics):

``

l1 := plot(X, t = 0 .. 16, thickness = 4, linestyle = dash, color = red):

 

``

Download fitting.mw

## i need to get a curve, but the graph is not displaying a curve fit

 

Hi. I am trying to solve a system of differential equations but I am having trouble understanding what I do wrong. I am a novice Maple user.

>with(PDEtools): with(LinearAlgebra): with(DifferentialGeometry): with(VectorCalculus): with(DEtools):

>_Omega_d := 1-_Omega_r

>eq1 := h1(z)*h2(z)+h2(z)*h3(z)+h1(z)*h3(z)-3*(_Omega_d*((1+z)^3)+_Omega_r*((1+z)^4)) = 0

>eq2 := h2(z)^2+h3(z)^2+h2(z)*h3(z)-1/3*(1+z)*(h2(z)*(diff(h2(z), z))+h3(z)*(diff(h3(z), z)))+_Omega_r*((1+z)^4) = 0

>eq3 := h1(z)^2+h3(z)^2+h1(z)*h3(z)-1/3*(1+z)*(h1(z)*(diff(h1(z), z))+h3(z)*(diff(h3(z), z)))+_Omega_r*((1+z)^4) = 0

>eq4 := h2(z)^2+h1(z)^2+h2(z)*h1(z)-1/3*(1+z)*(h2(z)*(diff(h2(z), z))+h1(z)*(diff(h1(z), z)))+_Omega_r*((1+z)^4) = 0

>sys := {eq2, eq3, eq4}

Equations eq1 - eq4 are my equations, but since eq1 does not have a differentiated function, I leave it out of the system, otherwise I get an error that states that I have more functions than variables.

>sys1 := subs(_Omega_r = 10^(-15), sys)

>ics := {h1(0.1e-3) = 1, h2(0.1e-3) = 1, h3(0.1e-3) = 1, (D(h2))(0.1e-3) = 4.500015, (D(h3))(0.1e-3) = 4.500015, (diff(h1(z), z))(0.1e-4) = 4.500015}

ics are my inititial conditions.

>pdsolve(sys1 union ics, {h1(z), h2(z), h3(z)}, type = numeric, generalsolution)

But when I run this, I get an error that says "Error, (in pdsolve/sys) found the independent variables {z} also present in the names of the functions of the system {}".

I have tried numerous different methods to solve this, and I get stuck every time. If anyone has any advice, I would appreciate it. I am trying to get solutions for h1(z), h2(z), h3(z) (to ultimately plot these functions versus z), if possible.

 

Hi, I want to use Maple to derive the eigenvectors of a 3x3 matrix A. I can obtian the 3 eigenvalues correctly by using eigenvalues(A), and the results are "u, -a+u, a+u". But after inputing eigenvectors(A), I can only get "[-a+u, 1, {r}], [a+u, 1, {r}], [u, 1, {r}]". All the 3 eigenvectors are written as {r}, I dont know why...and how can I tranform {r} into visiable results? 

I would be very appreciate if anyone could give me some help!

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