Richard Stallman: Difference between revisions
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'''Richard Matthew Stallman''', founder of the GNU Project, was an early adopter of APL, and used it to write a text editor as a high school student in the summer of 1969<ref>Stallman, Richard M. [http://www.lysator.liu.se/history/garb/txt/87-2-rms.txt "RMS Berättar"].</ref>. The same year, he also wrote a now famous rhyme: | '''Richard Matthew Stallman''', founder of the GNU Project, was an early adopter of APL, and used it to write a text editor as a high school student in the summer of 1969<ref>Stallman, Richard M. [http://www.lysator.liu.se/history/garb/txt/87-2-rms.txt "RMS Berättar"].</ref>. The same year, he also wrote a now famous rhyme: | ||
<blockquote>Rho, rho, rho of X<br>Always equals 1<br>Rho is dimension, rho rho rank.<br>APL is fun!</blockquote> | <blockquote>Rho, rho, rho of X<br>Always equals 1<br>Rho is dimension, rho rho rank.<br>APL is fun!<ref>Stallman, Richard M. [https://stallman.org/doggerel.html#APL "Doggerel"]</ref></blockquote> | ||
This plays on the fact that <source lang=apl inline>⍴X</source> gives the [[shape]] (length of each [[axis]]; "dimension") of <source lang=apl inline>X</source> while <source lang=apl inline>⍴⍴X</source> gives the [[rank]] (number of axes/dimensions) and since the number of axes is always a count, it is a single number, which has the shape <source lang=apl inline>1</source> if a [[vector]], and <source lang=apl inline>⍴</source> always returns a vector: | This plays on the fact that <source lang=apl inline>⍴X</source> gives the [[shape]] (length of each [[axis]]; "dimension") of <source lang=apl inline>X</source> while <source lang=apl inline>⍴⍴X</source> gives the [[rank]] (number of axes/dimensions) and since the number of axes is always a count, it is a single number, which has the shape <source lang=apl inline>1</source> if a [[vector]], and <source lang=apl inline>⍴</source> always returns a vector: | ||
Revision as of 17:00, 31 December 2019
Template:Biography also on Wikipedia
Richard Matthew Stallman, founder of the GNU Project, was an early adopter of APL, and used it to write a text editor as a high school student in the summer of 1969[1]. The same year, he also wrote a now famous rhyme:
Rho, rho, rho of X
Always equals 1
Rho is dimension, rho rho rank.
APL is fun![2]
This plays on the fact that ⍴X gives the shape (length of each axis; "dimension") of X while ⍴⍴X gives the rank (number of axes/dimensions) and since the number of axes is always a count, it is a single number, which has the shape 1 if a vector, and ⍴ always returns a vector:
⎕←X←3 1 4∘.+2 7 1 8
5 10 4 11
3 8 2 9
6 11 5 12
⍴X
3 4
⍴⍴X
2
⍴⍴⍴X
1
References
- ↑ Stallman, Richard M. "RMS Berättar".
- ↑ Stallman, Richard M. "Doggerel"