Re: array of matrices

[johnherro@aol.com (John Herro)]

boaz@usa.pipeline.com(Boaz Chow) writes:
> type Matrix is array (integer range <>, integer range <>) of integer;
> Your second method [creating an array of
> pointers to type Matirx] looks very good.
> But how can I retrive the size (or dimension)
> of the matrix?
     On the matrix pointed to, use the attribute 'Last with a subscript. 
For example, if we have

type Matrix is array(Integer range <>, Integer range <>) of Integer; 
type Ptr is access Matrix; 
... 
A : array(1 .. N) of Ptr; 
... 
A(1) := new Matrix(1 .. 5, 1 .. 15); 
A(2) := new Matrix(1 .. 15, 1 .. 7); 

then the upper bound of the FIRST dimension of the matrix pointed to by
A(2) is
A(2).all'Last(1),
              -
which is 15, and the upper bound of the SECOND dimension of the matrix
pointed to by A(2) is
A(2).all'Last(2),
              -
which is 7.  Similarly, 'First retrieves the lower bound, so in this
example A(2).all'First(1) and A(2).all'First(2) are both 1.  For one last
example, using A(1) instead of A(2), A(1).all'Last(1) is 5.
     The .all may be omitted in all of these, so A(1)'Last(1) means
A(1).all'Last(1).
     I hope this helps.
- John Herro
Software Innovations Technology
http://members.aol.com/AdaTutor
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