Using HSL
Queries service
Hyprotech runs a queries and information service which gives advice and answers questions on all HSL matters. Whether the query is administrative (to do with the availability of HSL) or technical (about features of specific packages, for example), the initial contact should be made through the HSL Manager
AspenTech Limited
C1, Reading International Business Park,
Basingstoke Road,
Reading, Berkshire RG2 6DT.Tel: +44 (0)118 9226405 Fax: +44 (0)118 9226401
e-mail: hsl@aspentech.com
Classifications
HSL packages are classified into groups, each associated with a major area of numerical mathematics, such as the solution of sets of linear of equations, calculation of eigenvalues and eigenvectors, or the minimization of functions of several variables. Within each group, there is a further classification into subgroups.
Naming convention
Each package is associated with a sequence of four characters. The first two characters are always alphabetic and identify the group and subgroup to which the program unit belongs; for example, the MA series solves systems of linear equations with real coefficients and the ME series is for systems with complex coefficients. The next two characters are numeric.
A Fortran 77 package has the sequence of four characters as its name. The fifth character, which is always alphabetic, is used to distinguish between the program units within the package. The sixth character of the name (or its absence) identifies the version. The possibilities are:
- Absent: Single precision.
- D: Double precision.
- I: Integer
- C: Single precision complex
- Z: Double precision complex
A Fortran 90/95 package has HSL_ followed by the sequence of four characters as its name, and consists of a set of modules. Most usually, a package will consist of a single and double precision version. Each module will have a name starting with the package name, for example,
- HSL_MA42_SINGLE
- HSL_MA42_DOUBLE
Finding the package to do the job
Normally, the first step in choosing a package will be to consult the catalogue. Its classification list and its comprehensive index should be useful in the initial search. Each entry summarizes a package. In addition, the HSL query service is willing to help users with the choice of package.
Specification documents
More detailed instructions on how to use an individual package is given in a separate HSL specification document. Each contains a copy of the summary from the catalogue, a detailed description of how to set up the arguments, a short description of the method and in most cases an example of using the package on a simple problem. It is assumed that the user has a basic knowledge of Fortran.
Conditions of using Library material
A licence is required prior to making any use of HSL or any package therefrom. Code from HSL may not be incorporated in programs which are offered for sale, licence or supply to third parties other than those already licensed to use HSL except with the expressed written permission of Hyprotech UK Ltd and on payment of an appropriate fee.
Free use of HSL 2007 by academics
While HSL 2007 is a commercial product, it is also available without charge to academics for teaching and academic research purposes. For full details, see hsl.rl.ac.uk/hsl2007/hsl20074researchers.html. This innovation is a direct result of much of the core funding for the Numerical Analysis Group at the Rutherford Appleton Laboratory being provided by a grant from the Engineering and Physical Science Research Council.
Free non-commercial use of HSL Archive by anyone
The HSL Archive is may be licenced without charge to anyone (in the UK and elsewhere), so long as the packages are not then supplied to a third party as part of another software package. Access to the HSL Archive is by way of the RAL HSL web page.