
Contents  vii 
5.6  The Simple Gaussian Case with a Linear Theory  91 
5.7  The General Linear, Gaussian Case  92 
5.8  Equivalence of the Three Viewpoints  95 
5.9  The 
F 
Test of Error Improvement Significance  96 
5.10  Derivation of the Formulas 
of 
Section 5.7  97 
6 
NONUNIQUENESS AND LOCALIZED AVERAGES 
6.1  Null Vectors and Nonuniqueness 
101 
6.2  Null Vectors of a Simple Inverse Problem  102 
6.3  Localized Averages of Model Parameters  103 
6.4  Relationship to the Resolution Matrix  104 
6.5  Averages versus Estimates  105 
6.6  Nonunique Averaging Vectors and A Priori 
Information  106 
7 
APPLICATIONS 
OF 
VECTOR  SPACES 
7.1 
7.2 
7.3 
7.4 
7.5 
7.6 
7.7 
7.8 
7.9 
Model and Data Spaces  109 
Householder Transformations 
111 
Transformations That Do Not Preserve Length 
The Solution of the Mixed-Determined  Problem  I18 
Singular-Value Decomposition and the Natural Generalized 
Inverse  119 
Derivation of the Singular-Value Decomposition 
Simplifying Linear Equality and Inequality 
Constraints  125 
Inequality Constraints  126 
Designing Householder Transformations  115 
117 
124 
8 
LINEAR  INVERSE  PROBLEMS  AND NON-GAUSSIAN 
DISTRIBUTIONS 
8.1 
L 
, 
Norms and Exponential Distributions  133 
8.2 
8.3  The General Linear Problem  I37 
8.4  Solving 
L, 
Norm Problems  138 
8.5  TheL-Norm  141 
Maximum Likelihood Estimate of the Mean of an Exponential 
Distribution  135