Greetings,

currently im working on a project in which i basically have to calcuate and plot a little solar system, using newton mechanic. The work is done, but as it appears, the solution simply cannot be true. In the given example you can see that the planets move in more or less straight lines. I presume that the error is somewhere in the solution of the system of differential equations, but i can't see where it is.

I am grateful for every advice.

PlanetenSpacecurve.mw

I m using the follwing commands for ploting the five differnt values of M

with(plots):
SDfd1 := odeplot(dsol[1], [eta, diff(f(eta), eta)], -1 .. 1, color = green, axes = box);
SDfd2 := odeplot(dsol[2], [eta, diff(f(eta), eta)], -1 .. 1, color = red, axes = box);
SDfd3 := odeplot(dsol[3], [eta, diff(f(eta), eta)], -1 .. 1, color = blue, axes = box);
SDfd4 := odeplot(dsol[4], [eta, diff(f(eta), eta)], -1 .. 1, color = black, axes = box);
SDfd5 := odeplot(dsol[5], [eta, diff(f(eta), eta)], -1 .. 1, color = pink, axes = box);
display([SDfd1, SDfd2, SDfd3, SDfd4, SDfd5], labels = ["η", "f ' (η)"],
    labeldirections = [horizontal, vertical], labelfont = [italic, 16], axes = boxed,
    axesfont = [times, 14], thickness = 3);

But i do not want in colors.....i need graph without colors in different styles. how can ? Moreover i need legend which must be in centre of graph or within the box. It must not on left, right ,up or below. can some one help ?

Hi everybody, 

Neither of these questions is vital but answers will be greatly appreciated

-------------------------------------------------------------------------------------------------
Question 1 :
Is it possible to manage programatically the character fonts in a printf command ?
(for instance to print some piece of text in bold font ... without selecting it and clicking the bold B of the toolbar)

-------------------------------------------------------------------------------------------------
Question 2 :

In order to have a nice render, I use to create my own format for printf command. For instance, when I have to “printf” some text I usually compute its length L and my “printf” format constructor contains a command  like  MyFormat := cat(“%”, L, “a”)

Unfortunately the length(…) command seems to be sensitive to accented characters :
                                     For people not familiar with french, "dégénéré"  (note the acute accents) means "degenerate".
length(“dégénéré”) returns 12
length(“degenere”) returns 8
… which of course leads to a very inelegant render, which is all I wanted to avoid

Why does “length” behave this way ?
Is it possible to bypass this annoyance while ensuring “dégénéré” has length 8 ?


Thanks in advance

Use the command 'matrix' to define a matrix, and how to call the first row elements of the matrix?

This method

a:=matrix([[1,2,3],[4,5,6],[7,8,9]]);

a[1..2,-2..-1], does not work? Why？

Download define-functions.mw

Hi

I would like to compute the limit as t goes to infinity.

Let delta be a given positive real number

restart;
assume(t, positive);

g := (t,delta) arrow  maximization(minimization(abs(x^(2^(-t))-y), y = 0 .. delta), x = 0 .. 1) ;

then I would like to compute the limit of g(t,delta) as t goes to infinity

Many thanks for any help

Hi

I would like to compute the limit as t goes to +infinity of

restart;
assume(t, positive);

g(t):=minimize(abs(x^(2^(-t))-1),x=1-delta.1+delta);

where delta is very small such that 1- delta is positive.

Then I would like to compute the limit as to goes to infinity of g(t)

Many thanks

Find the least number of moves and how many different ways that is achieved to win snakes and ladders with 1 die, with 2 dice, and how about 3 dice.  How to realize this with Maple?

Hello,

how do to inscribed cone in sphere ?

Thanks

Hi, i try the part of Real of the complex expression:

restart;
w := A*exp(-alfa(1+I)*y)+B*exp((1+i)*y);
            A exp(-alfa(1 + I) y) + B exp((1 + i) y)
u := Re(w);
          Re(A exp(-alfa(1 + I) y) + B exp((1 + i) y))

But does not work.

Regards.

This question explores the family of differential equations dy/dx=sqrt(􏰐 1 +􏰏( a*x )+ 􏰏 (2 *y)) for various values of the parameter a.  

For the case a = 􏰐 0 find the analytical solution that passes through the point (0, 1) and verify that this is a solution to the differential equation. Use this solution to find the value of y correct to 4 decimal placeswhen x=􏰐1. 

In maple i did

y:=(1/2)*x^2+sqrt(3)*x+1:
diff(y,x)
                             
i got the answer x + sqrt(3)

as shown in the markscheme. please cluld anyone help how to get y before this step and what to do after.

I have trouble solving this equation

fsolve(5000 = int(1/(0.1060444429e-1-0.2120888857e-1*X+0.1033933318e-1*X^2), X = 0 .. x), x)

It has a few points where the solution will go towards infinite, but that is not something that is an issue normally. I have no problems what so ever to solve this using my trusty TI-89, so Im wondering what needs to be done to actually solve this. I have tried giving an initial guess, and I have tried using solve, but it doesnt seem to do the trick.

Regards

Hi,

I need your help to classify the follwing set {0}, {1} and [0,1] are local attractor or not and in the case of local attractor how can we determine the bassin of attraction. 

ode:=diff(x(t),t)=sqrt(x(t));

how can we prove using maple which of {0}, {1} and [0,1] are local attarctor or not.

Many thanks

I have many linear equations as below(f,g,h,...,p, are linear of S,T,..,W):

y1=f(S[i,j],T[i,j],U[i,j],V[i,j],W[i,j]);

y2=g(S[i,j],T[i,j],U[i,j],V[i,j],W[i,j]);

y3=h(S[i,j],T[i,j],U[i,j],V[i,j],W[i,j]);

.

.

.

yn=p(S[i,j],T[i,j],U[i,j],V[i,j],W[i,j]);

Where (i,j)=(0,0),...,(I,J)

How ask Maple to write them in Matrix form as below:

AX=0

Where X is: X=Transpose{S[0,0],S[0,1],S[0,J],...,S[1,0],S[1,1],...,S[1,J],...,S[I,0],S[I,1],...,S[I,J],

                        T[0,0],T[0,1],T[0,J],...,T[1,0],T[1,1],...,T[1,J],...,T[I,0],T[I,1],...,T[I,J],...,W[I,J]}

Dear All,

I would like to plot the probability density function of a state variable obtained from solving differential equations. I have found that there are functions called "PDF" and "KernelDensityPlot" in the Statistics package, but they really confuse me. Could you please point me out? My code is as follows.

Ps. Is it possible to plot the PDF directly from the solution of dsolve() without discretizing the results? 

restart:
with(plots): with(DEtools): with(plottools):with(LinearAlgebra): with(Statistics):

v1:=1: f:=-4: v2:=2.515: omega:=1: epsilon:=0.001: k:=0:
sys:=diff(u1(t),t)=v1*u1(t)-(omega+k*u2(t)^2)*u2(t)-(u1(t)^2+u2(t)^2+3*z(t)^2)*u1(t),
     diff(u2(t),t)=(omega+k*u1(t)^2)*u1(t)+v1*u2(t)-(u1(t)^2+u2(t)^2+3*z(t)^2)*u2(t),
     diff(z(t),t)=z(t)*(-v1+3*u1(t)^2+3*u2(t)^2+z(t)^2)+epsilon*z(t)*(v2+f*z(t)^4):

t_start:=50: t_end:=300: dt:=0.05: fs:=1/dt:

solA:=dsolve({sys, u1(0)=0.6, u2(0)=0.6, z(0)=0.1},
             {u1(t),u2(t),z(t)},
              type=numeric, method=rkf45, maxfun=0,
              output=Array([seq(i,i=t_start..t_end, dt)])):

u1:=solA[2,1][..,2]:
u2:=solA[2,1][..,3]:
z:=solA[2,1][..,4]:

u0:=sqrt~(u1^~2+u2^~2+z^~2):

Phi:=z/~u0:

# How could I plot the probability density of Phi (y-axis) against Phi(x-axis)?

Probability_density_function_plot.mw

Thank you!

Very kind wishes,

Wang Zhe