system. Finally, we outline work now in progress to further generalize the 

 Bugsystem to provide for the analysis of movement in three dimensions. 



DEFINING A BEHAVIORAL RESEARCH LANGUAGE 



The Behavioral Research Language, or BRL, is a high level operator based 

 language that is tailored to the unique problems associated with the input, 

 scaling, analysis and display of video images of moving objects. BRL is an 

 interpretive language which runs as an application program on a good sized 

 minicomputer and relies heavily upon user interaction with a storage graphics 

 terminal to input, plot, edit and transform the data through image processing 

 functions. Image processing generally culminates in the computation of paths 

 or trajectories of the objects moving before the video camera. Sets of 

 trajectories may be merged together and the data may be transformed to yield 

 time series of behavioral variables (e.g., linear velocity, angular velocity, 

 direction of travel, etc). These results may then be analyzed statistically, and 

 the resultant data sets either listed numerically or plotted on the graphics 

 terminal. Thus, the Bugsystem consists of two basic subsystems: (l)an unique 

 image processing system for the frame-by-frame analysis of video data; and (2) 

 a signal processing system for the statistical analysis of equispaced time series. 



The key element to understanding and using BRL lies in grasping the 

 operator-operand-resultant nature of specifying functions or commands to the 

 system. The general command syntax is as follows: 



*Operator/sw/sw Operand-name /sw/sw Resultant-name/sw/sw nl, . . . n5, 



Where "*" is the prompting character, "Operator" is one of the available 

 functions (of which there are currently 88, with the list still growing), 

 "Operand-name" is the name of the input (or operand) data set, and the 

 numeric constants "nl" through "n5" are optional numeric constants which 

 govern details of the function of certain operators. The "/sw" denote optional 

 "switches" (the word is taken from minicomputer jargon) which are used as 

 operator modifiers or to supply special information to the operator being used. 

 All data sets are disk resident and are specified by a four-letter name that can 

 be used to denote an experimental condition, a two-letter extention that 

 specifies the type of data represented (e.g., "VI"-video, "PA"-path, 

 "LV"-hnear velocity, "CA"-catergorized, etc.), and a six letter front name that 

 can be used to identify the species studies and/or the date of the experiment. 

 The front name must be specified only when starting the system and remains 

 unchanged unless it is explicitly modified by the LOAD operator. Operator 

 names will henceforth be in bold upper case letters in the text. 



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