Difference between revisions of "Dot"

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(Created page with "{{Glyphbox|.}} The glyph '''dot''' or '''period''' refers to the <code>.</code> character. It represents several unrelated concepts, some derived from traditional mathemat...")
 
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* In [[SHARP APL]] and [[NARS2000]], the function derived from two functions operands, can also be called [[monadic function|monadically]] and then represents the [[Alternant]] (<source lang=apl inline>+.× Y</source>) which is a generalisation of [[wikipedia:determinant|determinant]]s and [[wikipedia:permanent|permanent]]s. Specifically, (<source lang=apl inline>-.× Y</source>) is the [[wikipedia:determinant|determinant]].
 
* In [[SHARP APL]] and [[NARS2000]], the function derived from two functions operands, can also be called [[monadic function|monadically]] and then represents the [[Alternant]] (<source lang=apl inline>+.× Y</source>) which is a generalisation of [[wikipedia:determinant|determinant]]s and [[wikipedia:permanent|permanent]]s. Specifically, (<source lang=apl inline>-.× Y</source>) is the [[wikipedia:determinant|determinant]].
 
* In [[SHARP APL]], with a function left operand and an array right operand, called ''ply'', is used for the [[Power Operator]] (<source lang=apl inline>f⍣k</source> in several other dialects).
 
* In [[SHARP APL]], with a function left operand and an array right operand, called ''ply'', is used for the [[Power Operator]] (<source lang=apl inline>f⍣k</source> in several other dialects).
* In all dialects but [[SHARP APL]], <source lang=apl inline>∘</source>, named [[nil]], is the [[enclose]]d [[empty]] [[numeric]] [[vector]], which may also be written <source lang=apl inline><⍳0</source>.
 
 
* In dialects that support [[object oriented programming]], for example [[APLX]] and [[Dyalog APL]], the dot is used to access members of objects.
 
* In dialects that support [[object oriented programming]], for example [[APLX]] and [[Dyalog APL]], the dot is used to access members of objects.
 
* In [[NARS2000]], two immediately adjacent dots, <source lang=apl inline>..</source>, form a bi-glyph, and represents the [[Sequence]] function (represented by the ellipsis, <source lang=apl inline>…<⍳0</source> in [[dzaima/APL]] and [[Extended Dyalog APL]]).
 
* In [[NARS2000]], two immediately adjacent dots, <source lang=apl inline>..</source>, form a bi-glyph, and represents the [[Sequence]] function (represented by the ellipsis, <source lang=apl inline>…<⍳0</source> in [[dzaima/APL]] and [[Extended Dyalog APL]]).

Revision as of 10:23, 13 May 2020

.

The glyph dot or period refers to the . character. It represents several unrelated concepts, some derived from traditional mathematical notation. The dot is one of the most overloaded APL symbols:

Due to its use in numeric constants, letting . be a dyadic operator that takes numeric operands or a function that takes numeric arguments, is potentially problematic or at least confusing:

      4.6
4.6
      4..6
4 5 6 
      4...10 ⍝ this parses as 4 .. 0.10
4 3 2 1
      4. .10
4 0.1
      4 . . 10
SYNTAX ERROR
      4 . . 10
              
Works in: NARS2000
APL glyphs [edit]
Information GlyphTyping glyphs (on Linux) ∙ UnicodeFontsMnemonics
Individual glyphs Jot () ∙ Right Shoe () ∙ Up Arrow () ∙ Zilde () ∙ High minus (¯) ∙ Dot (.)