NAG Fortran Libary - Decision Trees
Selecting the best routine
Decision Trees within many Chapter Introductions in the NAG Fortran Library Manual make finding the right routine easier and quicker than ever before.
The trees lead the user through some simple yes/no questions that categorize the problem and lead to suggestions of the most suitable routines to be used. For example, the following decision tree is one of several included in the chapter on Minimizing or Maximizing a Function (Chapter E04):
The following links will bring you to the location of the decision trees in the chapters indicated for the NAG Fortran Library Mark 21 documentation.
| Chapter Description | Tree Descriptions | Chapter & Links |
|---|---|---|
| Roots of One or More Transcendental Equations | Tree 1: Functions of One Variable Tree 2: Functions of several variables | Chapter C05 Link to PDF |
| Quadrature | Tree 1: One-dimensional integrals over a finite interval Tree 2: One-dimensional integrals over a semi-finite or infinite interval Tree 3: Multi-dimensional integrals | Chapter D01 Link to PDF |
| Ordinary Differential Equations | Tree 1: Initial Value Problems Tree 2: Boundary Value Problems | Chapter D02 Link to PDF |
| Partial Differential Equations | Tree 1 Tree 2: Elliptic Branch Tree 3: Hyperbolic branch Tree 4a: Parabolic branch Tree 4b: Branch for parabolic PDE in non-conservative form | Chapter D03 Link to PDF |
| Interpolation | Tree 1 | Chapter E01 Link to PDF |
| Curve and Surface Fitting | Tree 1 Tree 2 | Chapter E02 Link to PDF |
| Minimizing or Maximizing a Function | Tree 1: Selection chart for unconstrained problems Tree 2: Selection chart for bound-constrained, linearly-constrained and nonlinearly-constrained problems Tree 3: Linear programming Tree 4: Quadratic programming | Chapter E04 Link to PDF |
| Matrix Factorizations | Tree 1 Tree 2: Inverse of a real n by n matrix of full rank Tree 3: Inverse of a complex n by n matrix of full rank Tree 4: Pseudo-inverses | Chapter F01 Link to PDF |
| Eigenvalues and Eigenvectors | Tree 1: Eigenvalues and Eigenvectors of Real Matrices Tree 2: Eigenvalues and Eigenvectors of Complex Matrices Tree 3: Singular Values and Singular Vectors | Chapter F02 Link to PDF |
| Determinants | Tree 1 | Chapter F03 Link to PDF |
| Simultaneous Linear Equations | Tree 1: Black Box routines for unique solution of Ax=b (Real matrix) Tree 2: Black Box routines for unique solution of Ax=b (Complex matrix) Tree 3: General purpose routines for unique solution of Ax=b (Real matrix) Tree 4: General purpose routines fur unique solution of Ax=b (Complex matrix) | Chapter F04 Link to PDF |
| Least-squares and Eigenvalue Problems (LAPACK) | Tree 1: Real Symmetric Eigenvalue Problems Tree 2: Real Generalized Symmetric-definite Eigenvalue Problems Tree 3: Real Nonsymmetric Eigenvalue Problems Tree 4: Real Generalized Nonsymmetric Eigenvalue Problems Tree 5: Complex Hermitian Eigenvalue Problems Tree 6: Complex Generalized Hermitian-definite Eigenvalue Problems Tree 7: Complex non-Hermitian Eigenvalue Problems Tree 8: Complex Generalized non-Hermitian Eigenvalue Problems Tree 9 | Chapter F08 Link to PDF |
| Large Scale Linear Systems | Tree 1: Solvers | Chapter F11 Link to PDF |