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Tally: Difference between revisions
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Tally was introduced in [[A]] with the name "count" and symbol <source lang=j inline>#</source>. The same notation was carried forward to [[A+]], as well as [[J]] following [[Arthur Whitney]]'s suggestion. The primitive was present in [[NARS2000]] by 2010, with the name "Tally" and symbol <source lang=apl inline>></source><ref>NARS2000 Wiki. [http://wiki.nars2000.org/index.php?title=Tally&oldid=573 Tally]. Old revision: 2010-08-29.</ref>. The symbol <source lang=apl inline>≢</source> for Tally was introduced in [[Dyalog APL 14.0]], and quickly adopted by NARS2000. It was later added to [[GNU APL]] and has been included in many recent APLs based on Dyalog, such as [[ngn/apl]], [[dzaima/APL]], and [[APL\iv]]. | Tally was introduced in [[A]] with the name "count" and symbol <source lang=j inline>#</source>. The same notation was carried forward to [[A+]], as well as [[J]] following [[Arthur Whitney]]'s suggestion. The primitive was present in [[NARS2000]] by 2010, with the name "Tally" and symbol <source lang=apl inline>></source><ref>NARS2000 Wiki. [http://wiki.nars2000.org/index.php?title=Tally&oldid=573 Tally]. Old revision: 2010-08-29.</ref>. The symbol <source lang=apl inline>≢</source> for Tally was introduced in [[Dyalog APL 14.0]], and quickly adopted by NARS2000. It was later added to [[GNU APL]] and has been included in many recent APLs based on Dyalog, such as [[ngn/apl]], [[dzaima/APL]], and [[APL\iv]]. | ||
Before the addition of Tally (and [[Zilde]]), there were numerous ways to get the length of a vector as a scalar: | |||
<source lang=apl> | |||
''⍴⍴v | |||
(⍴0)⍴⍴v | |||
(⍳0)⍴⍴v | |||
(⍴v)[0] | |||
×/⍴v ⍝ shortest and obscure | |||
0⊥⍴v ⍝ shortest and obscurest | |||
</source> | |||
== External links == | == External links == | ||