 
  
  
  
  
 
In this section, we present some of the notation we use throughout the book. We have tried to use standard notation that would be found in any current publication on the subjects covered.
Throughout, we follow several conventions:
We define matrix  of dimension
 of dimension  and block dimension
 and block dimension
 as follows:
 as follows:

We define vector  of dimension
 of dimension  as follows:
 as follows:

Other notation is as follows:
 (or simply
 (or simply  if the size is clear from the
  context) denotes the identity matrix.
 if the size is clear from the
  context) denotes the identity matrix.
 = diag
 = diag denotes that matrix
 denotes that matrix  has elements
 has elements
   on its diagonal, and zeros everywhere else.
 on its diagonal, and zeros everywhere else.
 denotes the
 denotes the  th element of vector
th element of vector  during
  the
 during
  the  th iteration
th iteration