Hello,

I'd like to clean up my project a bit. In a chapter of a project I made lots of calculations and declared a many (30) variabeles (Table, Numeric, Formula, ..)

Is there a way to remove all variable's except specified one's? (If it is possible I don't want to use an external file to write it to and read it back after a restart)

Is there a way to do a "restart" and preserve only the one's (2) that I need for my next chapter?
Or if not, without a "restart" and remove all variables except specified one's?

Thanks for your help, 

What’s the simplest way to solve an algebraic equation in the complex domain?

For example,

I*(a+3*b)+2*b+5*a = 3+2*I

where a and b are real numbers.

One of my post graduate students chose the theme "Discrete Wavelet analysis of medical signals with Maple" for her thesis. I test, is it possible to support such reearch be Maplesoft &  what may be the form of such support, if it is possible?

• here is an exercise I got from a text book                                                                                                              calculate the first 10 terms of the following sequence :                                                                                              

                                                                                                                                                             u[n+1]=1/2(u[n]+2/u[n]) n>=0                                                                                                                          

• estimate the differences u[3]-sqrt(2) , u[4]-sqrt(2), u[5]-sqrt(2), and u[6]-sqrt(2) with a precision of 50 numbers                                    
• what can we conjecture about the sequence ?
• how to prove that conjecture with MAPLE ?

This is pretty similar to my last question. but I found this maple code on a website that is suppose to find a vertex coloring of a graph G. The output is is supposed to be a list for example like [3, table([y = 1, k = 2, c = 2, m = 3, h = 1, x = 1] where the first part (in this case 3) is the number of colors and 1,2,3 in the second part are the colors to which each vertex is assigned.  However, no matter what graph I run this on I get everything equal to 1. such as [1, table([y = 1, k = 1, c = 1, m = 1, h = 1, x = 1])]. Why is this happening?  

color:=proc(G)
  local i, j, C, U, V, total_used;
  V:=Vertices(G); total_used:=1;
  C[V[1]]:=1;

  for i from 2 to nops(V) do
    C[V[i]]:=0;
  end do;

  for i from 2 to nops(V) do
    U:={};
      for j from 1 to nops(neighbors(V[i], G)) do
      U:=U union C[neighbors(V[i], G)[j]];
       end do;
    j:=1;
    while member(j, U) do
      j:=j+1;
     end do;

    C[V[i]]:=j;
    if j>total_used then
      total_used:=j;
    end if;
   end do;
  [total_used, eval(C)];
end:

So the pseudocode I'm trying to translate into maple is for the greedy vertex coloring algorithm.

The pseudo code is:

Initialize:
1. for i = 1 to n do
2. f[i] := 0 (: no color assigned yet to vertex i :)
3. end(for)
Main loop:
4. for i = 1 to n do
5. let f[i] be the smallest positive integer
which is not in the set {f(j) : j ∈ adj[i]}
6. end(for)
7 return f

The closest I've gotten though is:

greedy := proc (G)

local i, j, n, k, L::list;

description "Take simple graph G and return a coloring of the vertices with at most Delta(G)+1 colors";

n := nops(Vertices(G));
L := [seq(x, i = 1 .. n)];
L := subsop(1 = c(1), L);
j := 1;
for i from 2 to n do
L[Vertices(G)[i]] := c(0)
end do;

for i from 2 to n do
   for k to i do
        if member(Vertices(G)[i], Neighbors(G, Vertices(G)[k])) then j := j+1
       end if; 
   end do;
L[Vertices(G)[i]] := c(j)
end do;
return L;
end proc;

Basically my procedure is returning more than delta+1 colors for most graphs, how can I edit it to fix this? I'm guessing the problem is somewhere in my nested loops. Also, I cannot use commands like greedycolor or isvertexcolorable. Thanks.

Hi,

Thank you very much for your idea in previous discussion: this is the link.

http://www.mapleprimes.com/questions/202744-Calculs-Using-Maple

I asked how can I plot the phase portrait of this system

Sys1 := {diff(r(t),t) = r(t)^2*sin(theta(t)), diff(theta(t),t) = -r(t)^2*(-2*cos(theta(t))^2+1)};

I get this answer:

1) For me it's not necessary to give an initial condition to plot the pharse portrait.

2) What is the line in this phase portrait.

3) Here, I try a second method using Matlab code, I get:

and this is the code:

[r, theta] = meshgrid(0:pi/4:2*pi, 0:pi/4:2*pi);
rdot =r.^2.*sin(theta) ;
thetadot = r.^2.*(1-2*sin(theta).^2);
quiver(r,theta,rdot,thetadot)
xlabel('r')
ylabel('theta')

the arrow in the phase portrait are not the same.

Can someone give me more clear information about this problem.

Many thinks.

Hi, I'm trying to write a maple procedure to differentiate a function from first principles and so far I have

First_Principle := proc (f); for f do A := simplify((f(x+h)-f(x))/h); Limit(A, h = 0) = limit(A, h = 0) end do end proc

and from there I have no idea where to go. Does anybody have any ideas? Thanks!

How to solve the inequality

with Maple?

My attempts were the following.

Warning, solutions may have been lost

Of course, this works

f(1);
,

but one wishes to describe the solutions in the dependence on the parameter a. Unfortunately, both

and

produce wrong outputs(An SCR has been submitted by me.).

Egor has two parents, four grandparents, and so on.
Write an explicit formula and a recursive formula for the number of ancestors Egor has if we go back n generations.                

what would be the figure back to 25 generations ?

hi..i am a problem with solving following ....please help me ....thanks alot

dsys3 := {10*f2(x)+12*(diff(f1(x), x))+14*f3(x) = 0, 2*(diff(f1(x), x, x))+4*(diff(f2(x), x))+6*(diff(f3(x), x)) = 0, 16*(diff(f3(x), x, x, x, x))+19*(diff(f3(x), x, x))+22*(diff(f1(x), x))+25*f2(x)+27*f3(x)+29*f3(x)+31+32 = 0, f1(0) = 0, f1(1) = 0, f2(0) = 0, f2(1) = 0, f3(0) = 0, f3(1) = 0, ((D@@1)(f1))(0) = 0, ((D@@1)(f1))(1) = 0, ((D@@1)(f2))(0) = 0, ((D@@1)(f2))(1) = 0, ((D@@1)(f3))(0) = 0, ((D@@1)(f3))(1) = 0}; dsol5 := dsolve(dsys3, 'maxmesh' = 500, numeric, range = 0 .. 1, abserr = .1, output = listprocedure); fy3 := eval(f3(x), dsol5); fy2 := eval(f2(x), dsol5); fy1 := eval(f1(x), dsol5)

ERROR.mw

Hej everyone,

I am trying to run a Maple script for multiple parameters on our cluster, so far so good. I found that I can pass for example a:=1 and b:=2 to a Maple script using

maple -c "a:=1;" -c "b:=2;" < script.mpl

Is that the best/only way? For convenience I would like to read the parameters from a file, my first idea was to work with sed, so I tried

maple $(sed -n 1'p' data) < script.mpl

This should take the first line from data (which is -c "a:=1;" -c "b:=2;"), so that I would expect to get the same result.
Unfortunately, this is not the case, only the first parameter a:=1 is passed correctly and non of the further parameters.

I've appended the files, I used.

This may be not a Maple problem but rather me making a mistake using sed, but maybe you can see where I made a mistake.

Thanks in advance,

Sören

Download script.mw

The mw-file has to be exported as an mpl-file first. In my case data just contains one line: -c "a:=1;" -c "b:=2;" -c "c:=3;" (I couldn't upload either)

Hi,

I have a problem with a 1D loockup table with a Data set file. It seems that there are some problems with the file but I don't understand which.

I tried to use a .xlsx file and the result is this error (note that the table in excel has 17 rows, so at the 18 there is nothing):

Then I tried with a .csv file and I had this error:

I put below the MapleSim file, is not completed: just to have a look at the errors and the attached file, so don't consider other things.

srpingdamper.msim

the .xlsx attached files is the following, while i'm not able to upload the .csv but it's the same one just saved as .csv:

damperTR.xlsx

Thanks a lot.

Hello people in Mapleprimes,

I want to know how to use apply rule in the following problem.

Please tell me how to do about this.

applyrule(2*F(K,L)=F(2*K,2*L),2*F(K,L));

returns F(2*K,2*L), which is right.

But, what I want to do is to apply the rule with holding n as general variable of real number.

But, what I can get through 

applyrule(n*F(K,L)=F(n*K,n*L),2*F(K,L));

is only 2*F(K,L) not F(2*K,2*L).

What should I write additinally to the above to have Maple calcurate and produce the outcome as F(2*K,2*L), F(3*K,3*L) and so on?

Best wishes.

Taro