Table

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Table (), or Ravel Items, is a monadic primitive function which returns a matrix formed by applying Ravel to each major cell of the given array. Table shares its glyph <source lang=apl inline>⍪</syntaxhighlight> with the dyadic function Catenate First.

Examples

For arrays of rank 1 or higher, the result is identical to applying Ravel to major cells:

<source lang=apl>

     {⍵(⍴⍵)}⍪5⍴⎕A

┌─┬───┐ │A│5 1│ │B│ │ │C│ │ │D│ │ │E│ │ └─┴───┘

     {⍵(⍴⍵)}⍪3 4⍴⎕A

┌────┬───┐ │ABCD│3 4│ │EFGH│ │ │IJKL│ │ └────┴───┘

     {⍵(⍴⍵)}⍪2 3 4⍴⎕A

┌────────────┬────┐ │ABCDEFGHIJKL│2 12│ │MNOPQRSTUVWX│ │ └────────────┴────┘ </syntaxhighlight>

A scalar argument is converted to a 1-by-1 matrix:

<source lang=apl>

     {⍵(⍴⍵)}⍪123

┌───┬───┐ │123│1 1│ └───┴───┘ </syntaxhighlight>

Properties

Table preserves the array's Tally (the number of major cells).

Table is equivalent to reshaping with the shape where all trailing axis lengths have been replaced by their product or, alternatively, the tally concatenated to the bound divided by the tally: <source lang=apl>

     ⍪2 3 4 2⍴⎕A

ABCDEFGHIJKLMNOPQRSTUVWX YZABCDEFGHIJKLMNOPQRSTUV

     {⍵⍴⍨(≢⍵),(×/⍴⍵)÷≢⍵}2 3 4 2⍴⎕A

ABCDEFGHIJKLMNOPQRSTUVWX YZABCDEFGHIJKLMNOPQRSTUV

     {⍵⍴⍨(1↑⍴⍵),(×/1↓⍴⍵)}2 3 4 2⍴⎕A

ABCDEFGHIJKLMNOPQRSTUVWX YZABCDEFGHIJKLMNOPQRSTUV </syntaxhighlight>

In languages where the Rank operator is available, Table is equivalent to <source lang=apl inline>,⍤¯1</syntaxhighlight>: <source lang=apl>

     (,⍤¯1)2 3 4 2⍴⎕A

ABCDEFGHIJKLMNOPQRSTUVWX YZABCDEFGHIJKLMNOPQRSTUV </syntaxhighlight> In languages where function axis is available, Table is equivalent to <source lang=apl inline>,[1↓⍳≢⍴Y]</syntaxhighlight>: <source lang=apl>

     {,[1↓⍳≢⍴⍵]⍵}2 3 4 2⍴⎕A

ABCDEFGHIJKLMNOPQRSTUVWX YZABCDEFGHIJKLMNOPQRSTUV </syntaxhighlight>

External links

Lessons

Documentation


APL built-ins [edit]
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