An ALGOL 68 Package for Implementing Graph Algorithms

13. Implementing Sparse Matrices for Graph Algorithms

Sparse matrices are a key data structure for implementing graph algorithms using linear algebra. This chapter reviews and evaluates storage formats for sparse matrices and their impact on primitive operations. We present complexity results of these operations on different sparse storage formats both in the random access memory (RAM) model and in the input/output (I/O) model. RAM complexity resu...

A One Pass Algorithm for Compiling ALGOL 68 Declarations

A Space-Saving Technique for Assigning Algol 68 Multiple Values

The undghtforward way of elaborating an assignation d :its in an ALGOL 68 implementation is (1): • elaborate the destination d and the source s, yielding a name N and a value V; • assign fire value V to the Elaine N. In many cases, the elaboration of s will consist of the ovation of a copy on the working stack of an already existing value V. This value is assigned to N by copying it once more i...

On the Transformational Derivation of an Efficient Recognizer for Algol 68

During the sixties two level van Wijngaarden grammars (2vwg) were introduced for the formal definition of Algol 68. Two level van Wijngaarden grammars provide a formalism suited for writing rigorous formal definitions which read like human prose. Both the context free and context sensitive syntax of Algol 68 are defined in 2vwg. However, the specification is not executable. The Extended Affix G...

An R Package for Implementing Multiple Evapotranspiration Formulations

The use of multiple evapotranspiration (ET) models is critical for exploring the ambiguity in the representations of ET processes. Although ensemble ET models are increasingly used to address this ambiguity, practical issues include: 1) the diversity of process representations, which require different input data and constants; 2) the diversity of nomenclature, terminology and units used in the ...