Partition: Difference between revisions

From APL Wiki
Jump to navigation Jump to search
No edit summary
(4 intermediate revisions by 2 users not shown)
Line 2: Line 2:


On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new '''division''' of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element):
On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new '''division''' of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element):
[https://tio.run/##SyzI0U2pTMzJT9dNrShJzUtJTfn/qLdP/VHf1GBXvZRHbROqNQxtH3UufNS7S/NRx/JHvWvAnC1AvhVQEVABkJWSVqJg8Ki7BSKQkllcABSshQgAjdEAUuHB6uquZal5JerqGurqwanFxZn5eQFFmSABBXX1FHV1zUddi4EKnSOBvLS8YqCA@v///w0VDBWMYPBRV5u6R6ZrYlFJhjoA Try it online!]
<source lang=apl>
<source lang=apl>
       1 1 2 2 2 2 2⊆'HiEarth'
       1 1 2 2 2 2 2⊆'HiEarth'
Line 8: Line 10:
└──┴─────┘
└──┴─────┘
</source>
</source>
{{Works in|[[Dyalog APL]]}}
Right argument elements can be skipped by having their corresponding left argument element be 0:
Right argument elements can be skipped by having their corresponding left argument element be 0:
<source lang=apl>
<source lang=apl>
Line 15: Line 18:
└──┴───┘
└──┴───┘
</source>
</source>
{{Works in|[[Dyalog APL]]}}
In the case where the left argument is [[Boolean]], Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function:
In the case where the left argument is [[Boolean]], Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function:
[https://tio.run/##SyzI0U2pTMzJT9dNrShJzUtJTfn/qLdP/VHf1GBXvZRHbROqNQxtH3UufNS7S/NRx/JHvWvAnC1AvhVQEVABkJWSVqJg8Ki7BSKQkllcABSshQgAjdEAUuHB6uquZal5JerqGurqwanFxZn5eQFFmSABBXX1FHV1zUddi4EKnSOBvLS8YqCA@v///w0VQNBAAZU2fNTVpu6RX66QWJSqUJlfaq/OBTRF41HnAqDEo65FmqiSAA Try it online!]
<source lang=apl>
<source lang=apl>
       1 1 1 0 1 1 1 0 1 1 1 1⊆'How are you?'
       1 1 1 0 1 1 1 0 1 1 1 1⊆'How are you?'
Line 26: Line 32:
└───┴───┴────┘
└───┴───┴────┘
</source>
</source>
{{APL built-ins}}
{{Works in|[[Dyalog APL]]}}
== See also ==
* [[Partitioned Enclose]]
* [[Cut (K)]]
* [[Partition representations]]
 
==External links==
===Tutorials===
* [https://chat.stackexchange.com/rooms/52405/conversation/lesson-7-apl-functions-#41436171 APL Cultivation]
===Documentation===
* [https://help.dyalog.com/latest/index.htm#Language/Primitive%20Functions/Partition.htm Dyalog]
* [http://microapl.com/apl_help/ch_020_020_590.htm APLX]
{{APL built-ins}}[[Category:Primitive functions]]

Revision as of 09:10, 9 July 2020

Partition (, ) is a dyadic function which splits its right argument into differently sized pieces as determined by the non-negative integer left argument. This article uses to distinguish Partition from Partitioned Enclose (which is always ), but the actual glyph used varies by dialect.

On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new division of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element):

Try it online!

      1 1 2 2 2 2 2⊆'HiEarth'
┌──┬─────┐
│Hi│Earth│
└──┴─────┘
Works in: Dyalog APL

Right argument elements can be skipped by having their corresponding left argument element be 0:

      1 1 2 2 2 0 0⊆'HiEarth'
┌──┬───┐
│Hi│Ear│
└──┴───┘
Works in: Dyalog APL

In the case where the left argument is Boolean, Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function:

Try it online!

      1 1 1 0 1 1 1 0 1 1 1 1⊆'How are you?'
┌───┬───┬────┐
│How│are│you?│
└───┴───┴────┘
      ' '(≠⊆⊢)'How are you?'
┌───┬───┬────┐
│How│are│you?│
└───┴───┴────┘
Works in: Dyalog APL

See also

External links

Tutorials

Documentation

APL built-ins [edit]
Primitives (Timeline) Functions
Scalar
Monadic ConjugateNegateSignumReciprocalMagnitudeExponentialNatural LogarithmFloorCeilingFactorialNotPi TimesRollTypeImaginarySquare Root
Dyadic AddSubtractTimesDivideResiduePowerLogarithmMinimumMaximumBinomialComparison functionsBoolean functions (And, Or, Nand, Nor) ∙ GCDLCMCircularComplexRoot
Non-Scalar
Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
Selection FirstPickTakeDropUniqueIdentityStopSelectReplicateExpandSet functions (IntersectionUnionWithout) ∙ Bracket indexingIndexCartesian ProductSort
Selector Index generatorGradeIndex OfInterval IndexIndicesDealPrefix and suffix vectors
Computational MatchNot MatchMembershipFindNub SieveEncodeDecodeMatrix InverseMatrix DivideFormatExecuteMaterialiseRange
Operators Monadic EachCommuteConstantReplicateExpandReduceWindowed ReduceScanOuter ProductKeyI-BeamSpawnFunction axis
Dyadic BindCompositions (Compose, Reverse Compose, Beside, Withe, Atop, Over) ∙ Inner ProductDeterminantPowerAtUnderRankDepthVariantStencilCutDirect definition (operator)
Quad names Index originComparison toleranceMigration levelAtomic vector