Hi,

Lets say we have some expression like

0.5* t^5 * r^-1 *V

is there some way in maple to determine the power of the variable t ?

My goal is to realize a procedure [lets call it PowerOfT() ]  , so that

PowerOfT( 0.5* t^5 * r^-1 *V) = 5

Thank you very much for your help.

Hi,

I tried to write a procedure which performs a differentiation on list elements:

list1:= [x^3 , 2x , 3]
list2:= [x^5, 2x^4 , 2x]

dList:=proc(a::list, b::list)::list;
    local res::list, i::integer, n::integer; 
    description "add list elements and diff";
    n:=min(nops(a), nops(b)) ;
res:=[seq(0, i=1..n)];
for i from 1 by 1 to n do
     res[i]:=diff(a[i]+b[i],x)
end do;
res;
end proc:


dList(list1,list2)

However the Line:  res[i]:=diff(a[i]+b[i],x)

causes the Error: Error, illegal use of an object as a name;

Can someone give me a hint how to fix this?

Thank you very much.

Hi,

I am trying to realize the following calculation in Maple.

$
  \left[\sum_{i=0}^n y_i(x) \partial_x^i , \sum_{j=0}^m z_j(x) \partial_x^j \right]  \\
=   \sum_{i=0}^n \sum_{j=0}^m \sum_{l=0}^i  \binom il y_i(x) \left( \partial_x^{i-l} z_j(x)\right) \partial_x^{l+j} \\
- \sum_{j=0}^m \sum_{i=0}^n \sum_{l=0}^j  \binom jl z_j(x) \left( \partial_x^{j-l} z_i(x)\right) \partial_x^{l+i} \ .

$

Is there a way to make maple understand d/dx as a differential opperator and calculate with it? When i for example try to calculate diff(d/dx, x) it should give me d^2/dx^2 as a result. Unfortunately i don't know how to realize this.

Basic problem is i don't know how to realize operator expressions in maple like for example:

f(x) d/dx      ( f(x) is a smooth function of x here )

where when applied to a function h(x) it should result in f(x) d/dx h(x) .

Is that possible?

Thank you very much in advance.