HDC: A subroutine library for image processing using Burt’s hierarchical discrete correlation

This paper describes a library of subroutines that efficiently implement Burt’s (1981) hierarchical discrete correlation (HDC). The subroutines are written in Professional FORTRAN for IBM PCs or compatibles. Subroutines are included for both even and odd forms of the HDC, as well as for the corresponding algorithms for pyramid processing. Odd width kernels of up to 7×7 pixels and even width kernels of up to 6×8 pixels can be programmed easily with these subroutines. Thus, this library contains the forms of HDC that are most widely used in image processing and visual modeling. I show the efficiency of this implementation by reporting the execution time of each subroutine for several image sizes. I also present a method that simulates rotation of the kernel in order to allow applying kernels without circular symmetry at the desired orientation.     

Controlling the Tektronix 4006 graphics terminal with OS/8 BASIC

Several BASIC-callable assembler subroutines are described that permit relatively straight-forward interaction with a Tektronix 4006 or equivalent graphics terminal. These routines enable input, alphanumeric output, and graphic output with or without automatic coordinate transformation. The routines can be used for the graphic presentation of data or, with additional laboratory routines, for stimulus presentation in psychological experiments.     

Comparative evaluation of computer-based tachistoscopes

Various methods of implementing a computer-based tachistoscope are compared. Software considerations are emphasized, but hardward issues are also examined. Three types of systems are identified: file-driven systems, sets of callable subroutines, and special languages. All have advantages in some circumstances. A system of callable subroutines is favored, together with a file-driven system written in the host language using the subroutines.     

Efficient estimation of sensory thresholds

Laboratory computers permit detection and discrimination thresholds to be measured rapidly, efficiently, and accurately. In this paper, the general natures of psychometric functions and of thresholds are reviewed, and various methods for estimating sensory thresholds are summarized. The most efficient method, in principle, using maximum-likelihood threshold estimations, is examined in detail. Four techniques are discussed that minimize the reported problems found with the maximum-likelihood method. A package of FORTRAN subroutines, ML-TEST, which implements the maximum-likelihood method, is described. These subroutines are available on request from the author.     

Building a programming language for a small computer: Reinventing the wheel

The language SP-12 for a PDP-12 computer is described. SP-12 is an example of how a special-purpose language can be constructed from a set of machine-language subroutines that are called by a simple interpreter. Symbolic source programs make it easy to learn the language. Preliminary translation of the source program into binary code, using an assembler, greatly increases the speed of the interpreter.     

Speech Perception: Cognitive Foundations and Cortical Implementation

ABSTRACT— Speech perception includes, minimally, the set of computations that transform continuously varying acoustic signals into linguistic representations that can be used for subsequent processing. The auditory and motor subroutines of this complex perceptual process are executed in a network of brain areas organized in ventral and dorsal parallel pathways, performing sound-to-meaning and sound-to-motor mappings, respectively. Research on speech using neurobiological techniques argues against narrow motor or auditory theories. To account for the range of cognitive and neural attributes, integrative computational models seem promising.     

Running laboratory experiments using the RSX operating system and FORTRAN on the PDP-11

A system of FORTRAN-callable subroutines designed to facilitate running laboratories with the RSX operating system on a PDP-11 computer is presented. The subroutines include ones to give the FORTRAN programmer timing capability, better control of CRT input and output, control of a parallel-bit input and output interface, control of an analog-to-digital interface, and control of a digital-to-analog interface.     

NOVA SKED II: A behavioral notation language utilizing the Data General Corporation real-time disk operating system

A software system (NOVA SKED) was developed for the experimental control and collection of data from operant behavior experiments that is compatible with the Data General Corporation real-time disk operating system (RDOS). NOVA SKED is based on the SKED state notation language originally implemented on Digital Equipment Corporation PDP-8 series of minicomputers. The system includes a compiler written in FORTRAN, a multitasking run-time system that can be configured to run up to 30 stations, a data back-up system, standard data manipulation programs and subroutines, and user manuals.     

EMOTLAB: Software for studying emotional signaling in economic bargaining games

EMOTLAB software creates a virtual social environment in which individuals interact via computer with a virtual interaction partner in a series of economic bargaining games. The virtual partner appears on the participant's computer screen as a digital image (e.g., video or picture file) during each trial. A key feature of EMOTLAB software is its ability to control both the strategic behavior and the emotion signaling behavior (e.g., anger vs. embarrassment) of the virtual interaction partner. By simply editing a series of text files that control the subroutines governing the different features of the experiment (payoff structure, number of trials, etc.), EMOTLAB can generate an essentially infinite number of different social bargaining situations in which participants earn monetary payoffs contingent upon their decisions. This paper provides an overview of this software and how one can edit various subroutines to generate a typical experimental session in which research participants encounter a virtual interaction partner who displays different emotional signals.     

Derivative free gradient projection algorithms for rotation

A simple modification substantially simplifies the use of the gradient projection (GP) rotation algorithms of Jennrich (2001, 2002). These algorithms require subroutines to compute the value and gradient of any specific rotation criterion of interest. The gradient can be difficult to derive and program. It is shown that using numerical gradients gives almost precisely the same results as using exact gradients. The resulting algorithm is very easy to use because the only problem specific code required is that needed to define the rotation criterion. The computing time is increased when using numerical gradients, but it is still very modest for most purposes. While used extensively elsewhere, numerical derivatives seem to be underutilized in statistics.     

Relocating 65xx software timing routines

Price’s (1979) machine language timing subroutines are modified to make relocation easier by means of relative branching commands and use of screen holes for data storage.     

Coding simultaneous experiments as independent FORTRAN subroutines

Simultaneous experiments can be coded as separate FORTRAN subroutines which pass requests for critical times and events to a coordinating subroutine named CHECK. These requests are stored in a “request table.” When all the experiments are temporally dormant, CHECK loops through the request table, checking each request. Whenever CHECK discovers that one of the requested times or events has occurred, it CALLs the subroutine of the appropriate experiment. In addition to supporting simultaneous experiments, this system permits a simpler style of programming experiments than that possible in unenhanced FORTRAN. This simplicity is largely due to the fact that the “loop and check” control structures are implemented in the CHECK subroutine and hence are transparent to the programmer.     

Graphics software and hardware for RT-11 systems

A general-purpose graphics package is described that allows the user to generate figures with a supraset of the basic CalComp plotting subroutines. The software runs under RT-11 on an LSI-11 with 28K words of memory. The graphics subroutine library is approximately 200 blocks long. The plotting tasks are passed over an RS 232 line to a simple extension of an inexpensive and commercially available graphics controller. The controller implements these tasks as plotting instructions to a color television, a vector display, and a digital plotter. The graphics subroutines are written in FORTRAN and are invoked by the user as subroutine calls from a FORTRAN program. The graphics controller is a modified Motorola “Micro Chroma 68 Kit.” The board is based on the 6808 microprocessor and 6847 video controller. It provides eight graphic modes from 64 by 32 eight-color graphics to 128 by 192 four-color graphics to 256 by 192 two-color graphics. The present software and hardware implements the graphics subroutines as 256 by 192 two-color graphics, as 512 by 512 vector graphics, and as stepping instructions for a digital plotter.     

Software timing for 6500 series microcomputers

Two machine language programs are presented for use in behavioral research requiring timing of reaction latencies, stimulus presentations, or intertrial intervals. Sample programs in BASIC show how to load and use the subroutines, and suggestions are made for possible modifications to a variety of situations.     

Tachistoscope simulation package

A system of FORTRAN-callable subroutines is described that enable a PDP-11/20 computer to function as a multichannel tachistoscope. Features of the system include multiple display buffering, dynamic buffer allocation, control of character size and density, provisions for user-generated characters and symbols, and routines for recording of both vocal and buttonpress responses.     

Using a general analysis of variance algorithm for covariance designs

Procedures are described which enable researchers to implement balanced covariance designs of from one to four independent variables. Use is made of three subroutines from IBM’s Scientific Subroutine Package which implement a general decomposition algorithm for balanced designs. FORTRAN instructions, illustrating the main calling program, are given.     

Minicomputer controller for a behavioral primate laboratory

To keep pace with the increased animal carrying load and research productivity of our facilities by perpetual modification of and additions to rigid hardwired equipment would have been a costly and time-consuming enterprise. Thus, a computer controller for the laboratory was an inevitable choice to replace our highly individualized analog and digital units. Our system is based on a minimally configured PDP-8/e, devoid of peripherals except for a Teletype, in which the first phase was guided by the intent to replace separate component instrumentation with a unified digital computer system. The interface design was confined to five different printed circuit boards which in combination could handle computer I/O, switch contact inputs, analog threshold inputs, and medium current output control. Our software package can be divided functionally into three parts: the program interrupt handler, the background control programs, and the resident subroutines.     

YEPS: Running real-time experiments on a timesharing system

The Yale experimental programming system is described. This system consists of user-callable subroutines and a set of modifications to the UNIX operating system which support the development and execution of real-time psychology experiments. The interactions between a timesharing operating system and the provision of real-time facilities for experiments are discussed.     

Implementation of experimental procedures in the PACER system of on-line control

PACER comprises an Executive and associated routines that together provide the run-time facilities commonly needed by experiment control programs. Although the implementation is specific to a particular PDP-11 installation, the nature of the support provided is of more general interest. Simple experimental procedures are straightforwardly handled by direct program control of timing and of external apparatus, and by direct inspection of the states of input lines connected to such apparatus. For more complicated situations, where events may not occur in a strict sequence, it becomes more convenient to make use of priority interrupts to inititiate response to events. Tasks to be performed under interrupt control are coded by the user as special subroutines known as “Actions.” It is a feature of PACER that the user can arrange for the Executive to run Actions automatically at specified times. The main program is then able to carry out processing that it would not be able to undertake if it had to make repeated checks on the time.