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With Mathematica and J: gasoline inventory simulation
Computational exercises and demonstrations appear frequently in the classes that I teach at Lafayette College. The software that I use for in-class demonstrations is usually Mathematica [4] or J [3]. I focus on one language or the other throughout the ...
Client-server HTTP communications made easy
This article covers the problem of making client requests to Web servers over HTTP. More specifically, this article addresses two interrelated problems, sending data to a Web server using the POST method and processing the request with a CGI script at ...
Automatic generation of APL programs
This paper describes the use of grammatical evolution to generate APL programs which perform some pre-required function.
Exercises and problems: solutions to the diagonal sums on spiral matrices
The answer to the sums of the diagonals of a 1001 by 1001 spiral matrix is 669,171,001. More interesting than the answer is the number of responses and the variety of solutions. Beside solutions from APL and J, I received solutions using C++, RoboBasic, ...
New problem: some diagonal fun
Let us have some fun selecting out diagonals from rank 2 and 3 arrays. It is really an exercise in using some of the lesser-used but powerful primitive APL functions. There are probably several ways to arrive at the solutions. Let's see what we get.
A solution to the diagonal sums on spiral matrices
This paper refers to the section Exercises and Problems, published in the September 2007 APL Quote Quad issue, Volume 35, Number 3, and to the problem Diagonal Sums on Spiral Matrices, proposed by Ray Polivka.