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Generating a canonical prefix encoding
Computer programs for generating a minimum-redundancy exhaustive prefix encoding are described. One program generates a Huffman frequency tree, another determines the structure functions of an encoding, and a third program assigns codes.
Comments on “a continued operation notation”
This note is intended to clarify and correct several points in a recent paper describing some notations for symbol manipulation by M. P. Barnett [Comm. ACM 6(August, 1963)].
Randomized binary searching with tree structures
A more efficient method of using tree structures is proposed, which utilizes both plus and minus branches in the search path. Very significant gains result when the search key includes alphabetic characters.
report on CCITT data communications study group meeting
Data communications was the subject of a two-week meeting held 24 September through 4 October 1963, in Geneva, Switzerland, by the International Telegraph and Telephone Consultative Committee (CCITT) Special Study Group A. Previous meetings of this group had been held in Geneva in April, 1960, and October, 1961. The CCITT has traditionally been responsible for all standardization activities involving the public telecommunications network of the world. Among the 150 participants, there were eleven USA representatives who represented the Government, various business machine companies and the common carriers.
FORTRAN subroutines for time series data reduction
For several years the author has been concerned with time series data reduction of guided missile data derived from tracking, telemetry and static test instrumentation. The data, which is acquired from many sources and comes in a great variety of formats and coding systems, must commonly be manipulated in a number of general ways before the calculation of functions specific to guided missile analysis is possible. The costs of programming many special purpose data reduction programs and the development time consumed in preparing and checking out these programs have strongly indicated the need for independent, general-purpose computer program modules or subroutines for data reduction. The philosophy arrived at by the author, is almost identical with that described in a recent publication by Healy and Bogert, and in a note by Bennet, but these individual module specifications are concerned with continuous functions, whereas the referenced article deals with spectral analysis.
A note on some compiling algorithms
Two compiling generators for arithmetic expressions are discussed: one presently in use in an experimental compiler, and an improvement suggested by K. Speierman of Burroughs.
Some effects of the 6600 computer on language structures
The problem of compiling efficient 6600 codes prompted the development of an intermediate language reflecting the structure of the machine, that is more easily manipulated in improving object program efficiency. The subject of this paper is the intermediate language and methods of manipulating it.
Compilations of a series of arithmetic statements are discussed. It is assumed that all functions and exponentials have been removed from these statements, and replaced by simple variables. For purposes of simplicity the treatment of subscripts is ignored.
A simplified 6600 structure is presented to illustrate the compiling method. Several assumptions are made for purposes of simplification, although there are cases in which the assumptions are violated in the actual machine.
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