I am tryng to write and solve within Maple the equations of movement for a single body subject to a gravitatinal field, F_=-GMm/r2

But I get an error message when trying to define the Angular Momentum which doesn't make sense for me.

Thank you for any help on this topíc.

restart; with(Physics[Vectors]); conventions, Setup(mathematicalnotation = true);
conventions, [mathematicalnotation = true]
r_ := rho*_rho;
r_ := rho _rho
_rho(t);
_rho(t)
rho(t);
rho(t)
v_ := diff(rho(t)*_rho(t), t);
/ d \ / d \
v_ := |--- rho(t)| _rho(t) + rho(t) |--- phi(t)| _phi(t)
\ dt / \ dt /
a_ := diff(%, t);
/ 2 \
| d | / d \ / d \
a_ := |---- rho(t)| _rho(t) + 2 |--- rho(t)| |--- phi(t)| _phi(t)
| 2 | \ dt / \ dt /
\ dt /

/ 2 \ 2
| d | / d \
+ rho(t) |---- phi(t)| _phi(t) - rho(t) |--- phi(t)| _rho(t)
| 2 | \ dt /
\ dt /

eq[1] := -G*M*_rho(t)/r^2-a_ = 0;
/ / 2 \ 2\
| G M | d | / d \ |
eq[1] := _rho(t) |- --- - |---- rho(t)| + rho(t) |--- phi(t)| |
| 2 | 2 | \ dt / |
\ r \ dt / /

/ / 2 \
| / d \ / d \ | d |
+ _phi(t) |-2 |--- rho(t)| |--- phi(t)| - rho(t) |---- phi(t)|
| \ dt / \ dt / | 2 |
\ \ dt /

\
|
| = 0
|
/
Eq[1, 2] := seq(Component(lhs(eq[1]), n) = 0, n = 1 .. 2);
/ 2 \ 2
G M | d | / d \
Eq[1, 2] := - --- - |---- rho(t)| + rho(t) |--- phi(t)| = 0,
2 | 2 | \ dt /
r \ dt /

/ 2 \
/ d \ / d \ | d |
-2 |--- rho(t)| |--- phi(t)| - rho(t) |---- phi(t)| = 0
\ dt / \ dt / | 2 |
\ dt /
NULL;

L_ := `&x`(r_, m*v_);
Error, (in Physics:-Vectors:-&x) found the unit vector _rho present also as a function _rho(t); either one form or the other - not both - can be present in an algebraic expression

HI, I am trying to solve two PDEs but in boundry conditions there is arising an error plz help.
Nazi.mw

Hello,

I have many tests to conduct on a MapleSim model. At each test simulations, I would like to change slightly some parameters.

As I have many tests to do (with different parameters), I would like to use a script so as to do like this :

Parameters test1
Launch MapleSim simulation
Store results of test 1

And so on ...

How can I do this kind of script ?

Is it possible to store the 3D animation results ?

Thank you for your help.

Hi,

I recently noticed that Maple 2015 has become irresponsive on mac (macbook pro) with the latest java release (Java 8 update 66). Did anywone experience the same problem ?

Hi,

I have a first order differential eq. for some variable say $r(x)$, where $x$ is the independent variable.

After solving this differential equation numerically, I want to use its solution in other expression for $r(x)$ and plot the expession with $x$.

Please let me know how to do it.

Thanks in advance.

I'm trying to use the CodeGeneration package to generate code for a series expansion. I'd like to wrap it in a function that specifies the arguments, so that the code generation package can generate a complete function definition along with definitions for all the temporary variables.

with(CodeGeneration):
f := proc(r): x->r end proc:
to_translate := f(convert(series(sin(x),x,20),polynom));

to_translate := proc (x) options operator, arrow; x-(1/6)*x^3+(1/120)*x^5-(1/5040)*x^7+(1/362880)*x^9-(1/39916800)*x^11+(1/6227020800)*x^13-(1/1307674368000)*x^15+(1/355687428096000)*x^17-(1/121645100408832000)*x^19 end proc

CodeGeneration['C']( to_translate );

Warning, procedure/module options ignored
double to_translate (double x)
{
  return(r);
}

Instead of using the value for 'r' passed in, CodeGenerate is producing a function which returns the bare symbol 'r' which is treated as a double. It shouldn't be an issue with lazy evalution because 'to_translate' is evaluated on the statement before the call to CodeGeneration, and to_translate has the full expression that I want to generate code for. How do I get CodeGeneration to produce the intented result?

psi = x^(4/5)*f(x, eta)/(1+x)^(1/20)

eta = y/(x^(1/5)*(1+x)^(1/20))

how can i (diff(psi, x))

how can i (diff(psi, y))

Has anyone solved this problem from an older Putnam paper?

An ellipse sitting in the first quadrant with its major axis parallel to the x axis is tangent to the positive x and y axes.

It slides clockwise within the first quadrant while maintaining tangency to both positive axes until its major axis is parallel to the y axis.

Prove that the locus of its centre is the arc of a circle.

I have crudely animated this motion by sliding the axes around the stationary ellipse. Is there a more elegant animation which slides the ellipse against stationary axes?

I have functions like

g := (y, t)->sin(y(t))

diff(g(y, t), t) # ok

How to determine the derivative below with maple :

diff(g(y, t), y(t))

Thanks

Hi everyone,

Can anybody help me to write a programme in maple? I want to do a loop that iterate from an integer from 0 to N where I want to write a prodedure, say, MEC(N). Then I want to organise the output into a list of three lists  [[min points],[escape],[capture]], which, if correct, should include all integers from 0 to N exactly once.

> MEC := proc (N)
local IsEmpty, Escape, escape, capture, minpoints, Capture, z, MinPts, ic;
IsEmpty := array(0 .. 2*N);
Escape := array(0 .. 2*N);
Capture := array(0 .. 2*N);
MinPts := array(0 .. N);
IsEmpty := true;
Escape := true;
Capture := true;
MinPts := true;

for ic from 0 to N do
if IsEmpty then
z := ic;
MinPts[ic] := true;
z := ic;
while z <= 2*N and F(z) <= 2*N do
z := F(z);
IsEmpty[z] := true;
Escape[z] := true
end do;

z := ic;
while z <= 2*N and Finv(z) <= 2*N do
z := Finv(z);
IsEmpty[z] := true;
Capture[z] := true end do fi;
end do;
return [MinPts(z), Escape(z), Capture(z)]
end proc;

There are two operations involved in the program which is the function F and F inverse called Finv. 
i need to produce the output which contain the list of integers exactly once.

I could not figure out which logical expression that I do wrong.

Thank you for your help!

How to find the value of alpha and beta?

thank you for helping

Download Qu_3.mw

How evaluate system of two integral equation by laplace transform ?

Download Qu_2_mapel.mwQu_2_mapel.mw

Hello everyone!

i want to make a triangle which height's is a. Sorry, my English is not very good!

And I writed it by C language, but It is not right in maple. and I don't know. Can you help me? thank you very much! triangle.mw

Hi all,

How can the black circle be visible?

Visible also below the 3D graph?

Best, perr7

B := spacecurve( [R*cos(t),R*sin(t),0] ,t=0..4*Pi,thickness=1, style=line, color=black);

animate( plot3d, [     P_Pi2(x,y,t)  ,  x=-4000..4000,y=-4000..4000 ], t=0..1, frames=10, transparency=0, style=surfacewireframe, labelfont=[times, roman, 25], orientation=[45,60,0], view=[-4000..4000, -4000..4000, 0..0.006], caption=typeset( theta=Pi/2 ) , axesfont=[times, 15], axes=frame, background=B   );

It's my first post on this forum so Hi everyone from Poland!

I have the following question.

Is it possible to force the Maple to obtain a result in a particular form? For example instead (a+b)³ I wan to have the result of the form: a³+3a²b+3ab²+b³. And I want to multiply the red brackets to receive a quadratic forms.

Below is a sample result that I get and I want it in a different form.

http://i65.tinypic.com/28k29hk.png

[IMG]http://i65.tinypic.com/28k29hk.png[/IMG]