Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I understand how Browse() works. Sometimes Maple crashes or fails for some programs. Is it possible to add print("here" ) into the the mla files in the library to identify why and where Maple fails?

 

Thanks

 

How do I simulate the follow stochastic differential equations. Thanks very much!

dx=x*(5-2*x-3*y-z)dt+5x*dB1(t);

dy=y*(4-*x-5*y-2z)dt+4y*dB2(t);

dz=z*(2-5*x-7*y-2z)dt+2z*dB3(t);

I want to plot the eigenvalues of a 4x4 matrix. I know how to determine the eigenvalues, but how do i plot them? Because i saw that plot only works with real numbers. The result is a column vector. 

Hi dears,

How can I detect two equivalent matrices? Is there any Maple command for this?

Also, Is there any command to verify that two matrices have the same Smith normalform?

Sincerely yours

I would like to return local variable y (line 4 in showstat) in the attached dummy procedure (s1) without manually adding any comment inside the procedure s1. This procedure is a simple one and easy to copy paste/or change. When we have a long procedure, it is difficult to do so. I will always know the name of the local variable I want (say, y) and/or line number in showstat

Thanks

PS, I want to get y:=array(1..,2[(1)=x,2=zz])
 

> 

restart;

> 

s1:=proc(n,x)
local y,xx,i,j,zz::array(1..n,1..n);
for i from 1 to n do for j from 1 to n do zz[i,j]:=x[i]*(1+x[j]^2);od:
od:
y:=array(1..2,[(1)=x, (2)=zz]):
for j from 1 to n do xx[i]:=zz[i,i]/(add(zz[i,j],j=1..n));od:
0;
end proc;

s1 := proc (n, x) local y, xx, i, j, zz::(array(1 .. n, 1 .. n)); for i to n do for j to n do zz[i, j] := x[i]*(1+x[j]^2) end do end do; y := array(1 .. 2, [1 = x, 2 = zz]); for j to n do xx[i] := zz[i, i]/add(zz[i, j], j = 1 .. n) end do; 0 end proc

(1)
> 

showstat(s1);

 

s1 := proc(n, x)

local y, xx, i, j, zz::array(1 .. n,1 .. n);

   1   for i to n do

   2     for j to n do

   3       zz[i,j] := x[i]*(1+x[j]^2)

         end do

       end do;

   4   y := array(1 .. 2,[1 = x, 2 = zz]);

   5   for j to n do

   6     xx[i] := zz[i,i]/add(zz[i,j],j = 1 .. n)

       end do;

   7   0

end proc

 

 
> 

x0:=Vector(2,[1,1]);

x0 := Vector(2, {(1) = 1, (2) = 1})

(2)
> 

s1(2,x0);

0

(3)
> 

 


 

Download showstatexample.mws

Dear All

I am trying to use differential operator two times in sucession but I am not getting desired differentiation. Please see content below:


 

> 

with(PDEtools):

> 

DepVars := [u(x, t), v(x, t), phi(x, t), psi(x, t)]; 1; declare(u(x, t), v(x, t), phi(x, t), psi(x, t))

[u(x, t), v(x, t), phi(x, t), psi(x, t)]

 

u(x, t)*`will now be displayed as`*u

 

v(x, t)*`will now be displayed as`*v

 

phi(x, t)*`will now be displayed as`*phi

 

psi(x, t)*`will now be displayed as`*psi

(1)
> 

_local(I):

> 

I := phi(x, t)*(diff(v(x, t), x)+b*(diff(u(x, t), x, x)))+psi(x, t)*(diff(u(x, t), x, x, x)+d*(diff(v(x, t), x, x)))

phi(x, t)*(diff(v(x, t), x)+b*(diff(diff(u(x, t), x), x)))+psi(x, t)*(diff(diff(diff(u(x, t), x), x), x)+d*(diff(diff(v(x, t), x), x)))

(2)
> 

ToJet(I, DepVars)

phi*(b*u[x, x]+v[x])+psi*(d*v[x, x]+u[x, x, x])

(3)
> 

T[1] := proc (f) options operator, arrow; diff(f, u[x]) end proc; 1; T[2] := proc (f) options operator, arrow; diff(f, u[x, x]) end proc; 1; T[3] := proc (f) options operator, arrow; diff(f, u[x, x, x]) end proc; 1; U[1] := proc (f) options operator, arrow; diff(f, v[x]) end proc; 1; U[2] := proc (f) options operator, arrow; diff(f, v[x, x]) end proc

proc (f) options operator, arrow; diff(f, u[x]) end proc

 

proc (f) options operator, arrow; diff(f, u[x, x]) end proc

 

proc (f) options operator, arrow; diff(f, u[x, x, x]) end proc

 

proc (f) options operator, arrow; diff(f, v[x]) end proc

 

proc (f) options operator, arrow; diff(f, v[x, x]) end proc

(4)
> 

d := proc (f) options operator, arrow; diff(f, x)+u[x]*(diff(f, u))+u[x, x]*(diff(f, u[x]))+u[x, x, x]*(diff(f, u[x, x])) end proc

proc (f) options operator, arrow; diff(f, x)+u[x]*(diff(f, u))+u[x, x]*(diff(f, u[x]))+u[x, x, x]*(diff(f, u[x, x])) end proc

(5)
> 

T[2](I)

0

(6)

Why this is giving zero result ?

If I change Ito jet notation then I get result non zero result like:

> 

T[2](phi*(b*u[x, x]+v[x])+psi*(d*v[x, x]+u[x, x, x]))

phi*b

(7)
> 

d(T[2](phi*(b*u[x, x]+v[x])+psi*(d*v[x, x]+u[x, x, x])))

0

(8)

I was expecting this to be "phi[x]*b, "but instead I am getting zero result.``


 

Download operator_for_differentiation.mw

Let us consider 

Student[Precalculus]:-LimitTutor(sqrt(x), x = 2);

One expects a nice illustration of the result sqrt(2). But instead of that one reads "f(x) approaches 1.41 as x approaches 2". This is simply clueless and forms a wrong understanding of limits. It should also be noticed that all the entries (left, 2-sided, and right) produce the same animation. The same issue with other limits I tried, e.g.

Student[Precalculus]:-LimitTutor(sqrt(x), x = 1);

. I think this command should be completely rewritten or excluded from Maple. 

I am working to minimize an objective function concerning a facility location problem (p-median technique).

Can somebody explain how to formulate the constraint equation that involves  1 or 0?

For instance, the constraint x[i,j]  is an element of {0,1}; namely, x[i,j] = 1 if a point is assigned to a facility located at the point j; 0 otherwise.

Thanks in advance.

 

I am attempting to minimize an objective function that is related to a p-median problem (facility location). Can somebody please tell me how to impose a constraint that comprises 0 or 1? For instance, I wish to assign the condition, x[i,j] = 0 or 1; in other words, x[i,j] = 1 if the point i is assigned to facilty located at point j; 0 otherwise.

 

Thanks in advance!

Hi!

I'm currently using Maple 17 and I'm trying to programatically export .eps 3D plots using the following code:

plotsetup(eps, plotoutput = `square_of_x`, plotoptions = `color=rgb , portrait, noborder, height=4in,width=4in, shrinkby=0.1`)

The problem that I'm facing is:

1- The z-axis label is outside of my figure (see uploaded figure). This happens even if I try to save the figure in .png and it seems that the 'shrinkby' option its not working properly;

Could you help me solving this?

Thanks!

 

Hi

I have a set P which is filled with 2D elements e.g.

P:={[1,1],[1,2],[1,3]...}


Later I'm wanting to add a new element e.g. {[1,10]}
At the moment I have

P union {[10, 10]}


If I were to print this I get what I want, but I want to update P.
When I try and do

 P:= P union {[10,10]}

I get an error "Error, illegal use of an object as a name"

What am I doing wrong and how can I solve this? Much appreciated!

I have upload the attachment here. in this problem I want to find the comparison. Please check it and please tell me the correction

 

Ask.mw

AB44.mwAdded these tasks by highlighting object and then choosing
Edit > Create Task

Is there some way to delete a task from my Tasks palette

At some point I created "My second palette" is there a way
to delete individual items from this palette and how are tasks
added to a customized palette.

Any help appreciated, Thanks! Les

AB44.mw

Hello!

Hope everything fine with you. Please check the following program

restart; a := 0; b := 1; Rd := .5; Ra := .2; Nc := .6; e := .2; Nr := .3; H := .9; Digits := 20;
with(LinearAlgebra);
L[0] := 1; L[1] := a+1-x;
M := 4; K := 1;
for n while n <= M do
L[n+1] := expand(-((x-2*n-a-1)*L[n]+(n+a)*L[n-1])/(n+1))
end do; printlevel := 2;
for m from 0 while m < M do
for n to 2^(K-1) do
psi[n, m] := simplify(sqrt(m+1/2.)*2^((1/2)*K)*(eval(L[m], x = 2^K*x-2*n+1)))
end do
end do;
f1 := simplify(sum(sum(c[p, q]*psi[p, q], q = 0 .. M-1), p = 1 .. 2^(K-1)));
u := collect(f1, [x], recursive);

u := -3.5276684147527874541*c[1, 3]*x^3+(4.4721359549995793928*c[1, 2]+21.166010488516724724*c[1, 3])*x^2+(-3.4641016151377545871*c[1, 1]-13.416407864998738178*c[1, 2]-34.394767043839677677*c[1, 3])*x+c[1, 0]+3.4641016151377545871*c[1, 1]+7.8262379212492639373*c[1, 2]+14.992590762699346680*c[1, 3]

f := 1+sum(A[i]*(x^(i+1)-(i+1)*x), i = 1 .. M-2)

f:=1+A[1]*(x^2-2*x)+A[2]*(x^3-3*x)

 

I want to equate the like powers of "x" in f ( mention as red) and u ( mention as red) for any values of M make a system of equations as

Eq[1]:=-3.5276684147527874541*c[1, 3] = A[2];

Eq[2]:=4.4721359549995793928*c[1, 2]+21.166010488516724724*c[1, 3] = A[1];

Eq[3]:=-3.4641016151377545871*c[1, 1]-13.416407864998738178*c[1, 2]-34.394767043839677677*c[1, 3] = -2*A[1]-3*A[2];

Eq[4]:=c[1, 0]+3.4641016151377545871*c[1, 1]+7.8262379212492639373*c[1, 2]+14.992590762699346680*c[1, 3] = 1;

and solve them for any values of A[1] and A[2];

Also attached the program Equate.mw

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

For the PDE, I can't seem to plot T' as the y-axis, it gives me the error, "Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct". Anyone knows what seem to be the problem? I am open to all ideas and would appreciate any help:)

fyp3.mw

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