Promote: Difference between revisions

From APL Wiki
Jump to navigation Jump to search
(Created page with "'''Promote''' is a monadic function that adds a length-1 axis to its argument before the other axes, resulting in an array with rank one higher. It appears as a primitive in Kap (<syntaxhighlight lang=apl inline><</syntaxhighlight>, "increase rank") and Dyalog APL Vision (<syntaxhighlight lang=apl inline>∧</syntaxhighlight>), as well as J (<syntaxhighlight lang=j inline>,:</syntaxhighlight>, "'''Itemize'''"), BQN (<code>≍</code>, "...")
 
No edit summary
 
Line 1: Line 1:
'''Promote''' is a [[monadic]] [[function]] that adds a length-1 [[axis]] to its argument before the other axes, resulting in an array with [[rank]] one higher. It appears as a [[primitive]] in [[Kap]] (<syntaxhighlight lang=apl inline><</syntaxhighlight>, "increase rank") and [[Dyalog APL Vision]] (<syntaxhighlight lang=apl inline>∧</syntaxhighlight>), as well as [[J]] (<syntaxhighlight lang=j inline>,:</syntaxhighlight>, "'''Itemize'''"), [[BQN]] (<code>≍</code>, "'''Solo'''"), and [[Uiua]] (<code>¤</code>, "'''Fix'''"). In J and BQN it's paired with the related dyadic primitive [[Laminate]]. The [[K]] primitive Enlist (<code>,</code>), which creates a length-1 list containing its argument, can also be interpreted as Promote because [[depth]] and rank are equivalent in the [[list model]] of arrays.
'''Promote''' is a [[monadic]] [[function]] that adds a length-1 [[axis]] to its argument before the other axes, resulting in an array with [[rank]] one higher. It appears as a [[primitive]] in [[Kap]] (<syntaxhighlight lang=apl inline><</syntaxhighlight>, "increase rank") and [[Dyalog APL Vision]] (<syntaxhighlight lang=apl inline>∧</syntaxhighlight>), as well as [[J]] (<syntaxhighlight lang=j inline>,:</syntaxhighlight>, "'''Itemize'''"), [[BQN]] (<code>≍</code>, "'''Solo'''"), and [[Uiua]] (<code>¤</code>, "'''Fix'''"). In J and BQN it's paired with the related dyadic primitive [[Laminate]]. The [[K]] primitive Enlist (<code>,</code>), which creates a length-1 list containing its argument, can also be interpreted as Promote because [[depth]] and rank are equivalent in the [[list model]] of arrays.


For an argument <syntaxhighlight lang=apl inline>A</syntaxhighlight>, promote can be implemented as <syntaxhighlight lang=apl inline>(1,⍴A) ⍴ A</syntaxhighlight> or <syntaxhighlight lang=apl inline>(⍳1) ∘.⊢ A</syntaxhighlight>. The choice to add an axis at the beginning is based on [[leading axis theory]], as this allows the axis to be placed in any other position using the [[Rank operator]].
For an argument <syntaxhighlight lang=apl inline>A</syntaxhighlight>, promote can be implemented with [[Ravel]] with [[Function axis|axis]] as <syntaxhighlight lang=apl inline>,[⎕IO-0.5] A</syntaxhighlight>, with [[Reshape]] as <syntaxhighlight lang=apl inline>(1,⍴A) ⍴ A</syntaxhighlight>, or with [[Outer Product]] as <syntaxhighlight lang=apl inline>(⍳1) ∘.⊢ A</syntaxhighlight>. The choice to add an axis at the beginning is based on [[leading axis theory]], as this allows the axis to be placed in any other position using the [[Rank operator]].


== Documentation ==
== Documentation ==

Latest revision as of 01:22, 6 February 2024

Promote is a monadic function that adds a length-1 axis to its argument before the other axes, resulting in an array with rank one higher. It appears as a primitive in Kap (<, "increase rank") and Dyalog APL Vision (∧), as well as J (,:, "Itemize"), BQN (≍, "Solo"), and Uiua (¤, "Fix"). In J and BQN it's paired with the related dyadic primitive Laminate. The K primitive Enlist (,), which creates a length-1 list containing its argument, can also be interpreted as Promote because depth and rank are equivalent in the list model of arrays.

For an argument A, promote can be implemented with Ravel with axis as ,[⎕IO-0.5] A, with Reshape as (1,⍴A) ⍴ A, or with Outer Product as (⍳1) ∘.⊢ A. The choice to add an axis at the beginning is based on leading axis theory, as this allows the axis to be placed in any other position using the Rank operator.

Documentation


APL built-ins [edit]
Primitives (Timeline) Functions
Scalar
Monadic Conjugate ∙ Negate ∙ Signum ∙ Reciprocal ∙ Magnitude ∙ Exponential ∙ Natural Logarithm ∙ Floor ∙ Ceiling ∙ Factorial ∙ Not ∙ Pi Times ∙ Roll ∙ Type ∙ Imaginary ∙ Square Root ∙ Round
Dyadic Add ∙ Subtract ∙ Times ∙ Divide ∙ Residue ∙ Power ∙ Logarithm ∙ Minimum ∙ Maximum ∙ Binomial ∙ Comparison functions ∙ Boolean functions (And, Or, Nand, Nor) ∙ GCD ∙ LCM ∙ Circular ∙ Complex ∙ Root
Non-Scalar
Structural Shape ∙ Reshape ∙ Tally ∙ Depth ∙ Ravel ∙ Enlist ∙ Table ∙ Catenate ∙ Reverse ∙ Rotate ∙ Transpose ∙ Raze ∙ Mix ∙ Split ∙ Enclose ∙ Nest ∙ Cut (K) ∙ Pair ∙ Link ∙ Partitioned Enclose ∙ Partition
Selection First ∙ Pick ∙ Take ∙ Drop ∙ Unique ∙ Identity ∙ Stop ∙ Select ∙ Replicate ∙ Expand ∙ Set functions (Intersection ∙ Union ∙ Without) ∙ Bracket indexing ∙ Index ∙ Cartesian Product ∙ Sort
Selector Index generator ∙ Grade ∙ Index Of ∙ Interval Index ∙ Indices ∙ Deal ∙ Prefix and suffix vectors
Computational Match ∙ Not Match ∙ Membership ∙ Find ∙ Nub Sieve ∙ Encode ∙ Decode ∙ Matrix Inverse ∙ Matrix Divide ∙ Format ∙ Execute ∙ Materialise ∙ Range
Operators Monadic Each ∙ Commute ∙ Constant ∙ Replicate ∙ Expand ∙ Reduce ∙ Windowed Reduce ∙ Scan ∙ Outer Product ∙ Key ∙ I-Beam ∙ Spawn ∙ Function axis ∙ Identity (Null, Ident)
Dyadic Bind ∙ Compositions (Compose, Reverse Compose, Beside, Withe, Atop, Over) ∙ Inner Product ∙ Determinant ∙ Power ∙ At ∙ Under ∙ Rank ∙ Depth ∙ Variant ∙ Stencil ∙ Cut ∙ Direct definition (operator) ∙ Identity (Lev, Dex)
Quad names Index origin ∙ Comparison tolerance ∙ Migration level ∙ Atomic vector
Retrieved from ‘https://aplwiki.com/index.php?title=Promote&oldid=10902’