MaplePrimes Questions

Hi all

I have written the following code in maple to approximate arbitrary functions by hybrid of block-pulse and bernstein functions but it doesn't work properly especially for f(t)=1.0, so what is the matter?

bb1.mws

 


best wishes

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Using Maple 18.01 on windows 7.

When setting typesetting level to extended, I get this (which is what I want):

restart;
diff(x(t),t);

But I also wanted to use alias, to make the above show just as \dot(x), i.e. without the (t) as well, since the equations are long, and not having (t) printed next to each letter would make them easier to read. But I found out that if I use an alias as follows

alias(x=x(t))

then now the typesetting level extended no longer works:

restart;
alias(x=x(t));
diff(x,t);

What do I need to make Maple display  only \dot(x) without the argument (t) everywhere?

 

 

 

 

I have written a code that computes the fourier-bessel series of a function over the period [a,b].
When I wanted to get some numerical results, I noticed that it takes lots of time for maple to numerically compute the coefficients of the series. Each coefficient of the series is expressed in terms of some integrals that I was expecting maple to compute them in few seconds, however, when  I want to compute "N=100" terms of the series, it takes lots of time.

I was wondering if there is any way to boost up the numerical computation time. I will appreciate any help.

Below you can find my code.

Example_2.mw

Many many thanks for your attentions! :)

can maple 17 make serial communication with arduino such as i wan to get data from accelerometer then the data will display in maple 17

Hi,

I need to transfer an array of size (M,N) from maple to matlab. But i dont know how to make it. Please help me for this. Thanx in advance.

Regards

Sunit

In using the Maple 17 VectorCalculus package I was suprised to find that the Norm of a free vector is not the same as the Norm of a "corresponding" RootedVector, i.e.the same vector with a different root. Am I missing something ? Thanks for an explanation.

 

restart;
with(VectorCalculus):

P:=<1,2,3>; # free vector
PP:=RootedVector(root=[-1,2,-3],P)

Norm(P);
Norm(PP);

Hi all,

I have a problem when creating package by using 'read' function to concatenate package's elements

Case1: Create package normally, Proc1 and Proc2 are exported

restart;
###################################
# Define package Test contains 2 proc: Proc1 and Proc2
##################################
Test := module()
    option package;
    export Proc1, Proc2;

    Proc1 := proc()
        description "Proc1() is an element of package Test";
        printf("In Proc1\n");
    end proc;
    Proc2 := proc()
        description "Proc2 is an element of package Test";
        printf("In Proc2\n");
        Proc1();
    end proc;
end module;

#################################
# Try to call Proc1 from Proc2
#################################
Test:-Proc2();

Console output:

> Test:-Proc2();
In Proc2
In Proc1

==> The result looks OK

 

Case2: Split Proc1 into another file and include it into master file by using 'read' function, Proc1 and Proc2 are exported

restart;
###################################
# Define package Test contains 2 proc: Proc1 and Proc2
##################################
Test:= module()
    option package;
    export Proc1, Proc2;

    ###########################
    # Code to concatenate "Proc1.maple" here
    ###########################

    read "Test/Proc1.maple";

    Proc2 := proc()
        description "Proc2 is an element of package Test1";
        printf("In Proc2\n");
        Proc1();
    end proc;


end module;


#################################
# Try to call Proc1 from Proc2
#################################
Test:-Proc2();

Console output:

> Test:-Proc2();
In Proc2
                                    Proc1()

==> The Proc1 seem does not execute or evaluate

 

Case3: Split Proc1 into another file and include it into master file by using 'read' function, just export Proc2, not export Proc1

restart;

###################################
# Define package Test contains 2 proc: Proc1 and Proc2
##################################
Test:= module()
    option package;
    export Proc2;

    ###########################
    # Code to concatenate "Proc1.maple" here
    ###########################

    read "Test/Proc1.maple";

    Proc2 := proc()
        description "Proc2 is an element of package Test1";
        printf("In Proc2\n");
        Proc1();
    end proc;


end module;


#################################
# Try to call Proc1 from Proc2
#################################
Test:-Proc1();

Console output:

> Test:-Proc2();
In Proc2

In Proc1

==> The result looks good

 

Please help to explain the problem from case 2 and case 3. If I want to split package proc into many files, how can I do?

 

Hi! I'm trying to solve a system of four non-linear equations in Maple 17 but it doesn't work.

Equations are: F, Fw, Ft, Fk and varibles are T,w,k,ki.

Parametars are Mn=10, Ms=2, alfa=0.2 and Tf=(k*T^(alfa)/Mn)^(1/alfa).

Solutions must be positive. 

This is maple script:

restart;
> assume (w>0):
> assume (T>0):
> assume (k>0):
> assume (ki>0):
> assume (Mn>0):
> assume (Ms>0):
> assume (Tf>0):
> assume (alfa>0):


> Gp:=1/exp(sqrt(w*I));

> Cf:=((T*w*I+1)/(Tf*w*I+1));

> Cpi:=(k*w*I+ki)/(w*I);

> L:=Cf*Cpi*Gp;
> L:=evalc(L):
> F:=subs(Ms=2,Tf=(k*T^(alfa)/Mn)^(1/alfa),evalc(abs(1+L)^2-1/Ms^2));
> F:=subs(Mn=10,alfa=0.2,evalc(F));

> Fw:=diff(F,w):
> Fk:=diff(F,k):
> Ft:=diff(F,T):
> fsolve({F,Fw,Fk,Ft},{w,k,ki,T});

Thanks in advance for any help. Dragoslav

Hi there

I've got an 18*18 matrix which almost all of its elements are in parametric form. I Need to export this matrix to MATLAB to do some numerical alnalysis on that But when I click on  " export as MATLAB", the following error appears:

"can not convert matrix elements to float[8] datatype"

I wonder if thre's a solution to that or anyother way to move the matrix(as it is) to MATLAB.

I'll be appreciated your help

This seems such a simple/basic question I'm almost too embarassed to ask.

Anyway. this is causing me some headaches

 

> A := <0|0>;

         A:= [0 0 ]

> B := A:

> A(1,1) := 2 ;

         A:= [2 0 ]

> B;

         B:= [2 0 ]

What do I do to prevent the elements of B changing if A changes, after using the assignment B:=A (or should I not be using this assignment?)  I mean, I would like the same behaviour as 

> a := 0;

         a:=0

> b := a;

         b:=0

> a := 2;

         a:=2

> b;

         b:=0

which seems to work as I "expect"...

I'm used to Mathcad, and I am very new to Maple. Something I cannot figure out right now is how to define multiple elments of a matrix using a function.


Input Data

Define system dimensions as n:=2;

i:=1..n;

j:=1..n;

lambda:=Matrix(n);

Lambda:=Matrix(n);

upsilon:=vector(n); 

Minor side note: I originaly had upsilon defined using the syntax "Vector[row](ncomp)", but this was giving me an 'exponentiation' operation error, so I changed it to what it is now (basically a list/array, which I guess has different type definitions that no longer cause the error?).

lambda[1,2]:=471.0433;

lambda[2,1]:=883.7530;

upsilon[1]:=58.69;

upsilon[2]:=18.07;

The Problem I'm Having

Now I just want to define Lambda using a function to define all elements (like I would in Mathcad).

Lambda[i,j]:= (upsilon[j]/upsilon[i]) * exp (-lambda[i,j]/2853);

which gives me an extremely long error message:

Error, invalid input: exp expects its 1st argument, x, to be of type algebraic, but received Matrix(2, 2, {(1, 1) = -0.3504976272e-3, (1, 2) = -.16509955895845776, (2, 1) = -.30975332953088164, (2, 2) = -0.3504976272e-3}, datatype = float[8]

As far as I can tell (keep in mind that this is my very first Maple project) that it doesn't like lambda as a matrix? But shouldn't it just evaluate to the element? and why is (2,2) and (1,1) giving values, because it should intialize to zero, so exp(0) = 1 in these cases??

I tried to simplify further by just trying

Lambda[i,j]:=(upsilon[j]/upsilon[i]);

but then it just gives me 1, and when I look into Lambda all the elements are now 1 when only the diagnol elements should be 1 (the rest some fractional amount)??

I am at a complete loss. I thought about doing something like For i = 1 to n etc. but then it just looks like coding, which defeats the purpose of trying to make a calculation sheet documenting the procedure...

Any help and/or insights into what I am doing wrong here would be most welcomed :)

P.S. I've just noticed that there is an upload option :/ Wilson_Equation.mw.

 

I do the following:

restart; 
z := x + y;
type(z, specfunc(name, `+`));

However the result is 'false'. How to correct my type checking?

 

``

restart:

 

C=2;

C = 2

(1)

w[2]*s[1]+w[1]*s[2];

s[1]*w[2]+s[2]*w[1]

(2)

C=3;

C = 3

(3)

(w[3]*s[2]+w[2]*s[3])*s[1];

(s[2]*w[3]+s[3]*w[2])*s[1]

(4)

C=4;

C = 4

(5)

((w[4]*s[3]+w[3]*s[4])*s[2]+w[2]*s[3]*s[4] )*s[1];

((s[3]*w[4]+s[4]*w[3])*s[2]+w[2]*s[3]*s[4])*s[1]

(6)

C=5;

C = 5

(7)

(((w[5]*s[4]+w[4]*s[5])*s[3]+w[3]*s[4]*s[5] )*s[2]+w[2]*s[3]*s[4]*s[5] )*s[1];

(((s[4]*w[5]+s[5]*w[4])*s[3]+w[3]*s[4]*s[5])*s[2]+w[2]*s[3]*s[4]*s[5])*s[1]

(8)

C=6;

C = 6

(9)

((((w[6]*s[5]+s[6]*w[5])*s[4]+w[4]*s[5]*s[6])*s[3]+w[3]*s[4]*s[5]*s[6])*s[2]+w[2]*s[3]*s[4]*s[5]*s[6])*s[1];

((((s[5]*w[6]+s[6]*w[5])*s[4]+s[5]*s[6]*w[4])*s[3]+s[4]*s[5]*s[6]*w[3])*s[2]+s[3]*s[4]*s[5]*s[6]*w[2])*s[1]

(10)

 

``


Download pattern.mw

 

This probably isnt too difficult to write a procedure to generate the expression, given C=2,3,4,5,...

But I may be thinking too much and stuck...

 

Also, I am thinking that if it is possible to use something like a "fibonacci sequence", in the famouse example here, which uses the in a procedure. Probably, we dont need to use this.

 

Thanks,

 

casper

 

I have been learning to use the Physics package in Maple 18.  I just updated to the latest version of the Physics package to see if it would fix the problem by my results are the same.

When I take a covariant derivative in spherical coordinates it does not appear to have a scale factor such as g_kk below.  

 A_(j;k)=1/(g_(kk))(partialA_j)/(partialx_k)-Gamma_(jk)^iA_i,

This definition of comes from the Mathworld web site.  I think they have a typo such that it should actually read h_k which is the scale factor instead of g_kk which is the metric.  They are related by h_k^2 = g_kk.

Why doesn't Maple's covariant derivative have the scale factor when I am differentiating in spherical coordinates?

Thanks!

 

 While calculating an integral including complex numbers, I have encountered with the output "undefined if a+ib>0". What does this mean?A complex number bigger than zero???

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