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I have the following procedure to do the above. It works but it returns [9,10],[10,9],[12,1] for n=1729(for example). How do I modify this to 

a) to count 9,10 and 10,9 as the same and hence only show one of them

b) get 1,12 to show as a solution?

cubesum:=proc(n::nonnegint)
global listcub:=table();
local k:=0, x:=iroot(iquo(n,3),3),y:=x,x3:=x^3,y3:=y^3;
if 3*x3 <> n then x=x+1; x3:=x^3;y:=x;y3:=x3 end if;
while x3<=n do
y:=iroot(n-x3,3); y3:=y^3;
if(x3+y3 = n) then k:=k+1; listcub[k]:=[x,y]end if;
x:=x+1; x3:=x^3;
end do;
convert(listcub,list);
end proc:

 

Hy all its my first post, thankyou for having me.
I'm not sure why this happens but say I got a list

X := [0, 1, 2, 3];

and perform this expression

sum(sum(a[k]*X[i]^k, k = 0 .. n), i = 1 .. nops(X))

I get output 4*a[0]+6*a[1]+14*a[2] which is correct and what I want, but if I swap the summations

to 

sum(sum(a[k]*X[i]^k, i = 1 .. nops(X)), k = 0 .. n)

I get 3*a[0]+6*a[1]+14*a[2] which is incorrect I believe, unless I'm being silly and missing something.

this happens because its a 0 in my list, if I replace a zero with a non zero number then it works fine and if I replace my set with

X := [seq(x[i], i = 0 .. 3)];
both summations give me
a[2]*x[0]^2+a[2]*x[1]^2+a[2]*x[2]^2+a[2]*x[3]^2+a[1]*x[0]+a[1]*x[1]+a[1]*x[2]+a[1]*x[3]+4*a[0]

and at the end there is 4*a[0]
nothing that is really depending on any element in the list. so why when I replace an element with 0 using the second expression (which should be equivalent to first) gives me less a[0]I really would like to understand why this is happening

any insight or assistance would be gratefully appreciated.(I'm still a noob)

I have a nice family of functions of the form:

W:=(p,n,mu,w)->sum(w[k] * (n-k)* mu(n-k),k=1..n)

which can be evaluated for different p's using the operator mu*diff(...,mu)

The recursion begins with p=0 and proceeds using mu*diff(W(p,n,mu,w),mu) = W(p+1,n,mu,w).

Can anybody implement this procedure in Maple

Thank you 

How can I make transformations like:

sum(a*u[k]+b*v[k],k=1..n) into a*sum(u[k],k=1..n)+b*sum(v[k],k=1..n)

and in the opposite direction?

I wish to convert:

Sum(x[k],k=1..n)*Sum(y[k],k=1..m) -> Sum(Sum(x[j]*y[k],j=1..n),k=1..m)

Can anybody show me an elegant way to do it?

Gracias

Why is it that


dismantle(3*a);

returns a SUM entity?


SUM(3)
   NAME(4): a
   INTPOS(2): 3

dismantle(3+a);

also returns a SUM entry

SUM(5)
   NAME(4): a
   INTPOS(2): 1
   INTPOS(2): 3
   INTPOS(2): 1

ToInert() looks fine for both of these.

 

Tested on Maple 16, Maple 17, Maple 18

Dear all:

I wisth to replace in an expression that contains several sums:

sum(a[i],i=1..n+1) and sum(w[i],i=1..n+1)

and replace them with a single command into:

a[n+1]+sum([i],i=1..n) and w[n+1]+sum(w[n],1..n)

everywhere in the expression

Thank you

Claudio

Hey all, I am new to the Maple software.

I have a question: how to find sum of all elements in a sequence?

For example , A:=[1,2,3,4]  the stupid way to find the sum is add them together by : A[1]+A[2]+A[3]+A[4]=10

Is there a better way to sum them together?

Surely this is a bug.

> 0^0;
                 1 
> sum( 0^m, m=0..infinity );
                 0

I'm trying to find the partial sum of the function. Now I need to plot the first couple partial sums onto 1 graph.

I'm not really sure how to input the plot function. I was able to graph it by inputting each partial sum function but I would prefer an easier solution.

The limit of

G := N -> sum(1/N*numtheory[sigma](k)/k,k=1..N ) 

as N -> infinity should be Pi^2/6. However

eval( G(N), N=infinity );

returns 0.

Can anyone explain this puzzling behaviour?

Hi,

This may be just my lack of maple syntax, however I cannot seem to find a way to add upper indicies in tensors (without first converting them to some other object, array, matrix etc)

In the physics package an example is just the metric tensor. 

I am trying to do something like this:

 

with(Physics);

add(g_[~mu,2], mu=1..2) 

Is there an easy way of summing upper indicies? Obviously lower indicies work, because the add/sum command recognizes the variable to iterate. 

Thanks in advance,

Age

 

Hi guys

 

I have an if statement inside a function. This function then get's called in a sum. However, the result is not correct as the if statement checks wether the argument equals 0, but since the sum passes only the summation index name, it doesn't work as intended.

How can I tell Maple, that it has to evaluate the index before passing it on? MWE appended.

 

Cheers

NOh

Comm := proc (n) options operator, arrow; `if`(n = 0, 1, 0) end proc;

proc (n) options operator, arrow; `if`(n = 0, 1, 0) end proc

(1)

Comm(0);

1

(2)

sum(Comm(j), j = 0 .. 0);

0

(3)

``

 

Download MWE.mwMWE.mw

Consider the following sum:


We know that if k is between 1 and N, the result will be



and otherwise the sum is zero.

How can I tell maple to compute this sum in each case without giving numerical values to the parameters "N" and "k"?

Thanks. :)

Hi Again

Assume that we have known matrix namely, Q, of order (m+1)*(m+1) and we want to construct following matrix

where 0(bar) is zero matrix of orde (m+1)*(m+1) and New matrix should be of order {N*(m+1)}*{N*(m+1)} where N is known constant.

thanks for any guide


Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

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