Maple has two kinds of variables or names as Maple calls them.
There are strings like x, sin, Pi, which are of
type string and indexed names or subscripted variables
like which are of type indexed.
These examples are input A[1], A[i,j], A[i][j] in Maple.
Most functions in Maple accept both kinds of variables.
The Maple type name means either a string or a subscript.
Example
> type(a,string);
true
> type(a,name);
true
> whattype(A[1]);
indexed
> type(A[1],indexed);
true
> type(A[1],name);
true
If is an indexed name, then the nops function returns the
number of indices, and the op function returns the
'th index.
Also
returns the name of the index. Example
> nops(A[i,j]);
2
> op(1,A[i,j]);
i
> op(0,A[i,j]);
A
> nops(A[i][j]);
1
> op(1,A[i][j]);
j
> op(0,A[i][j]);
A[i]
Functions work very similarly to indexed names. The syntax for a function call is
where is the name of the function, and
are the arguments.
The nops function returns the number of arguments,
and the op function returns the
'th argument.
Also op
returns the name of the function.
Example
> nops(f(x,y,z));
3
> op(1..3,f(x,y,z));
x, y, z
> op(0,f(x,y,z));
f
We can now create and pick apart any Maple formula. Exercise 6 asks you to write a Maple program that picks apart a Maple formula. We conclude here with some examples showing how this can be done interactively.
> f := sin(x[1])^2*(1-cos(Pi*x[2]));
2
sin(x[1]) (1 - cos(Pi x[2]))
> whattype(f);
*
> op(1,f);
2
sin(x[1])
> op(1,op(1,f));
sin(x[1])
> op(1,op(1,op(1,f)));
x[1]