f01rdf

f01rdf © Numerical Algorithms Group, 2002.

Purpose

H F01RDF Operations with unitary matrices, compute QB or Q B after factorization by F01RCF

Synopsis

[b,ifail] = f01rdf(a,theta,b<,trans,wheret,ifail>)

Description

 
 The unitary matrix Q is assumed to be given by
 
                                        H
                         Q=(Q Q   ...Q ) ,
                             n n-1    1  
 
 Q  being given in the form
  k                    
 
                               (I 0 )
                            Q =(0 T ),
                             k (   k)
 
 where
 
                                        H
                        T =I-(gamma) u u ,
                         k          k k k
 
                              ((zeta) )
                              (      k)
                           u =(z      ),
                            k ( k     )
 
 (gamma)  is a scalar for which Re (gamma) =1.0, (zeta)  is a real
        k                                 k            k      
 scalar and z  is an (m-k) element vector.
             k                     
 
 z  must be supplied in the kth column of A in elements 
  k                                                    
 a     ,...,a    and (theta) , given by
  k+1,k      m,k            k        
 
                  (theta) =((zeta) ,Im (gamma) ),
                         k        k           k
 
 must be supplied either in a    or in THETA(k), depending upon 
                             k,k                               
 the parameter WHERET.
 
 To obtain Q explicitly B may be set to I and pre-multiplied by Q.
                                        H                       
 This is more efficient than obtaining Q . Alternatively, F01REF 
 may be used to obtain Q overwritten on A.
 

Parameters

f01rdf

Required Input Arguments:

a (:,:)                               complex
theta (:)                             complex
b (:,:)                               complex

Optional Input Arguments:                       <Default>

trans (1)                             string   'n'
wheret (1)                            string   's'
ifail                                 integer  -1

Output Arguments:

b (:,:)                               complex
ifail                                 integer