Do-It-Yourself Learning: APL and J: Secret treasures of Math, part 1.

Many of you now probably use the pocket calculator type apps available for “smart” phones, as we once used a pocket calculator.   At the time, the pocket calculator was a Godsend for the math impaired. Those who were not confident of their math accuracy found that the calculator delivered us from the wrong answers. About 25 years ago, I mentioned my problems with math phobia to my late friend and computer  mentor Murry Ecker.  Murry said that it so happened that another  friend of his, who belonged to the local Astronomy club, had introduced him to APL. Murry told me APL might help me with my problems. He gave me a floppy disk with a copy of I-APL.

APL stands for A Programming Language. APL was developed by Dr.  Kenneth Iverson.  It was first used on IBM mainframe computers and accessed by computer terminals. It required a custom terminal with a special set of symbols. Dr. Iverson had an unusual background. He grew up on a farm in the province of Alberta, Canada.  During high school, he was pulled out of school so that he could do his farm chores. At night, he studied Calculus. He served in the Royal Canadian Air Force in World War II and eventually found his way into the Ph.D. program at Harvard in Mathematics.  Later, he worked on further development of APL at IBM.

APL became the standard programming language for advanced mathematics in the mainframe era. It is still used today in certain insurance and financial applications.

During the 1980’s, British APL Association, an organization of math teachers in Britain, ported APL to a variety of home computer operating systems  including DOS. I still occasionally use the DOS version of I-APL. If you have a computer with DOSBox  or other MS-DOS emulator,  conceivably you could still use I-APL. But it’s almost impossible to find the books you need to learn how to use it.

About the time I was learning I-APL, Dr. Iverson was finishing up the development of J. J was the improved version of APL that eliminanted the special symbols used in APL.  J uses the ASCII symbol set available on standard keyboards. Most of the British APL users moved to J. In this discussion, so shall we.

In the next post, I’ll show you how to use a few simple commands to create a multiplication or times table. You can use this to bone up on things you should have learned by the third grade, and at the same time show you the advanced matrix mathematics capabilities of J.

About Richard Rollo

I am a retired Community College Instructor. I taught Political Science 1 American Government for 22 years in Southern California. I am originally from Northern Minnesota. My earliest years were spent in the living quarters of a rural Duluth Winnipeg & Pacific Railway Depot. Then my family joined the great 1950's migration to Southern California where I joined up with fellow baby boomers in overcrowded schools.
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