## How to output a statistic of a list of items...

If input ["1","1","2","2","2","77"]

output a graph such as

1 has 2 times

2 has 3 times

77 has 1 time

## How to take the integral from a function solved nu...

3.mw

There are 2 questions actually. The first as the title says is about taking the integral. I have 2 functions that were found numerically from the system of differential equations (see the file), and I need to take the integral of the expression that includes both of them. Maple gives me something like Int () = Int (), so it doesn't solve anything. Why can it be?

The second question is about varying the boundary conditions. If, for example, I have the system with the condition like R(x_0)=R_0, can I get the plot  of R(x,R_0)? In my case I need to vary conditions on R and mu (R(0)=R_0 and mu(0)=mu_0) and then get the plot of the integral in relation to R_0 and mu_0. Is it even possible?

Hello,

I have two simple module's:

1) ------------------------------------------------------------------------

Point := proc(xx::float,yy::float)     return module()         local x := xx,y := yy;         export ShowPoint,GetX,GetY;                  ShowPoint := proc()             printf("Point X,Y -> [%f,%f]",x,y);         end proc;

        GetX := proc()             return x;         end proc;                 GetY := proc()             return y;         end proc;         end module: end proc:

2) ------------------------------------------------------------------------

PointMath := module()     option package;       export +;          + := proc(a::Point(float,float),b::Point(float,float))         option overload;         Point(a:-GetX()+b:-GetX(),a:-GetY()+b:-GetY());     end proc; end module: 

------------------------------------------------------------------------

Next I use first module:

p1:=Point(1.2,1.4);

p2:=Point(1.0,2.0);

Finally I want to add above two points:

with(PointMath)

p2:=p1+p2

The results is:

p2:=p1+p2

Why is not called operator '+' and two points are not added?

Best,

Rariusz

## Select remove in partitition...

Hi

How can I remove a subset containing a number from a partition?

eg S := [seq(2..5)]

P:=combinat:-setpartition(S, 2);

[[[2, 3], [4, 5]], [[2, 4], [3, 5]], [[2, 5], [3, 4]]]

I want to remove any partition involving 5

leaving

[[[2, 3]], [[2, 4]], [[3, 4]]]

i tried

remove(has,P,5)

## How to change a string of binary numbers into a ch...

"01000001" is A

how convert string of binary into a characters?

and

how to convert this string into 65 too?

## How to write a general table for get value with a ...

Primetable :=table[(2=b,3=c)]

so far, hard code in above code

is there a generic code for general

according alphabet order 5=d,7=e etc

## Monte Carlo simulation of one dimensional harmonic...

I want to use maple2015 to perform a Monte-Carlo simulation of a one dimensional Harmonic Oscillator.

Consider a particle having displacements, x=na where n is an integer, i.e 0 plus minus one, etc.

The potential energy of the particle is given by U(x)= 1/2 kx^2 = 1/2 ka^2 n^2.

For this simulation will choose ka^2 = 0.01 k_B T where k_B is Boltzmann's constant, and T is the temprature in Kelvin.

So we should perform a Monte-Carlo simulation starting from x(0)=20a, and perfroming individual steps by selecting an attmept to move x=+-a ,with equal probability, and choose whether to make the actual step according to energy change expected in that step.

I need to draw particle's position and x(t), and particle's energy E(t).

After that I need to calculate and draw the autocorrelation functions \phi_x(t) and \phi_E(t).

I found some code that might help me, but I am nor sure how to implement the above two lines on maple; your help is appreciated.

http://pubs.acs.org/doi/suppl/10.1021/ed100414p/suppl_file/ed100414p_si_001.pdf

## How to get the first minimum factor of an integer?...

Op(1,ifactor(12))

is 2^2

it has power

how to get 2 only

## Setting Display Precision in Startup Code...

Hi,

I'm trying to set the display precision at the start of the worksheet and using the command

interface(displayprecision = 4):

seems to work fine. However, it seems to have no effect when I put it in the startup code instead.  Am I doing something wrong or does the startup code execute differently somehow?

Thanks

## Incomplete worksheet...

I'm studying for an exam and earlier today I was working in my Maple sheet. I saved it as usual and no .bak file was in the directory afterwards. When I now later in the day tried to open it, I got the pop up message:
"There were problems during the loading process. your worksheet may be incomplete" and half of the content is missing.

I've searched on google and tried to solve it myself, unfortunately without any luck.

I would really appreciate any help.

Best regards

## Multivariable functions f(x1,x2,x3)...

Hi!

I am trying to convert expressions into functions, but the expressions have many variables x1, x2, x3.....xn.
The reason I am doing this is because I am hoping that differentiating functions in a large jacobian with large multivariable functions will go faster with functions than expressions. If it doesn't go faster then let me know.

What I am trying to do in a simplified code,

xv:=Vector(2,symbol=x):
f[1]:=x[1]+x[2];
f[2]:=x[1]-x[2];

f[1]:=unapply(f[1],[xv[1],xv[2]]);

Diff(f[1],x[1]);

f1:=x[1] + x[2]
f2:=x[1] - x[2]
f1:=(x_1, x_2) -> x_1 + x_2
d
------ f[1]
dx[1]

How can I get this to work? And is it worth it?

## How to modify the list of items in a drop down box...

Hi everybody,

I use a maplet that contains a DropDownBox named DDB.
This DropDownBox has a list named MyList
I want to replace MyList by a new list named MyNewList

The syntax given in the Maplets[DropDownBox] help page is
Maplets :-Tools :-Set(DDB(itemlist)=MyNewList)

This command returns the error
error in Set, invalid option for  ‘DDB(itemlist)’  ….

Is it a bug or some misuse (in the help page the “itemlist” option is written itemlist* : what is the meaning of this “*” ?)

As always any answer will be greatly appreciated.

## Is there a command for the sign of a permutation?...

I produce a list of permutations with "permute".

For each produced permutation, I want to have its sign (1 for even, -1 for odd).

Is there a command for that?

## problem with solving inequality...

Dear all,

I am trying to solve this inequality:

0 < 2*b^2*(10*K*a+3*K*b-sqrt((K+(2*K*a+1)/b)^2-4*K/b)*b+5)

for a.

However, I get to the error below:

Error, (in testeq) invalid arguments
does anyone know which mistake I am making?!!

what is this testeq?!