13.2 Arrays

One-dimentional arrays.

Typically stored in continous locations

+--+--+--+--+--+--+--+--+  
|  |  |  |  |  |  |  |  |  
+--+--+--+--+--+--+--+--+

Two-dimensional arrays

• Continuously by rows (or columns) order.

  	address(A[1,1]) + (i-1)*N + (j-1)
  =	(address(A[1,1])-N-1) + i*N + j
  =	constant + i*N + j

• Seperate area for each row
  +---+  
  |   |     +--+--+--+--+--+--+--+--+  
  | ------->|  |  |  |  |  |  |  |  |  
  |   |     +--+--+--+--+--+--+--+--+  
  +---+  
  :   :  
  :   :  
  :   :  
  +---+  
  |   |     +--+--+--+--+--+--+--+--+  
  | ------->|  |  |  |  |  |  |  |  |  
  |   |     +--+--+--+--+--+--+--+--+  
  +---+

• Hash addressing based on the indeces i and j of the entries A[i,j]. Mainly for sparse matrices.

Dynamic arrays

• A template (or dope vector) is allocated at compile time
      +--------------+  
      |     base     |  
      +---+----------+  
      | n | constant |  
      +---++---------+  
      | L1 | U1 | d1 |  
      +----+----+----+  
      | L2 | U2 | d2 |  
      +----+----+----+  
      :    :    :    :  
      +----+----+----+  
      | Ln | Un | dn |  
      +----+----+----+  
   
  A[ L1:U1 ; ... ; Ln:Un ]

• Entries are inserted at run time