J is used for the development of algorithms for a variety of statistical calculations including means, medians and quartiles, frequency tabulations, variances and covariances, regression analysis, graphical presentation, analysis of variance, random number generation and simulation, nonparametric tests, and probability distributions. Apart from the first two sections the organization of the paper is determined by the presentation of the statistical concepts with topics from J being introduced as required.
J4.01 script file: jcomp.ijs
A program for the minimization of a function of an arbitrary number of variables using the algorithm given in "A simplex method for function minimization" by J. A. Nelder and R. Mead, The Computer Journal, vol. 7, 1965, pp. 308 - 313.
Acrobat file: jsimplex.pdf
J4.01 script file: jsimplex.ijs
Some reflections on forty-five years of reading and programming and teaching programming languages with an emphasis on the array language J. This paper is a revision of Some Thoughts on J and Other Languages which is no longer available.
J4.01 script files: mostlyj.ijs, loom.ijs
A two-page introduction to J intended to be printed back-to-back, folded twice and used as a brochure.
J4.01 file: brochure.ijs
Programming languages are introduced briefly and a distinction is made between conventional and array languages. The language J is given as a modern exemplar of array languages and is illustrated with a few simple examples. Some comments are given on the teaching of languages and on the history of computing.
J4.01 file: Not available
A J tutorial with examples chosen mostly from elementary statistics. The principal J verbs are summarized so that they may be used independently as a statistical package.
J4.06 file: jtsp.ijs
J4.06 file (Statistical Package only): jsp.ijs
J601 file (Statistical Package only): jsp601.ijs
A simulation to illustrate machine-language programming for a one-address decimal computer with an order code of 15 instructions.
J4.06 file: comp.ijs
This program simulates machine-language programming for the Royal McBee LGP-30 computer. The 21-page paper, "The LGP-30: The University of Alberta's First Computer", discusses the experience with the LGP-30 at the University of Alberta and describes the simulator in some detail.
Acrobat file: The LGP-30: ...
J4.06 file: lgp30.ijs
A second LGP-30 simulator completed in February 2006 which uses programmed binary arithmetic operatios rather than the J floating-point operations is also available.
J4.06 file: lgp30mk2.ijs
This paper is a less technical version of A Lecture on Array Languages given above and is intended for the general reader.
Acrobat file: MyLife.pdf
J4.06 file: Not available
The Windows form given in the script file uses Cliff Reiter's treatment of one-dimensional three-cell automata given in his Fractals Visualization and J. Second Edition to view any of the 256 possible models. The parameters are the image size, and the paths to the J logo and to the directory for saving images. Radiobuttons are used to select a first row which contains either a random selection of occupied cells or a single centre occupied cell, and also to select the two colours used to diplay the images. The model number, a non-negative integer initially 0, may be specified arbitrarily or allowed to go through the sequence 0, 1, 2, ..., 255.
J4.06 file: automatn.ijs
3 141 59265 3589793 238462643 38327950288 4197169399375 105820974944592 30781640628620899 8628034825342117067 |
Clifford A. Reiter, Lafayette College
Ewart Shaw, University of Warwick
Home page: http://www.cs.ualberta.ca/~smillie/