combinat::compositions

Compositions of an integer

Use only in the MuPAD Notebook Interface.

This functionality does not run in MATLAB.

Syntax

combinat::compositions(n, <MinPart = k>, <MaxPart = l>, <Length = m>)

Description

combinat::compositions(n) returns all compositions of the nonnegative integer n.

A composition of a nonnegative integer n is a list of positive integers with total sum n.

Examples

Example 1

We output all compositions of the integer 4:

combinat::compositions(4)

Example 2

It is possible to output only the compositions of a certain length:

combinat::compositions(4, Length=2)

Example 3

The options MinPart and MaxPart can be used to set constraints on the sizes of all parts. Using MaxPart, you can select compositions having only small entries. This is the list of the compositions of 4 with all parts at most 2:

combinat::compositions(4, MaxPart=2)

MinPart is complementary to MaxPart and selects compositions having only large parts (it takes a non-negative value). This is the list of the compositions of 4 with all parts at least 2:

combinat::compositions(4, MinPart=2)

By default, the parts of a composition have to be positive. This can be changed using the option MinPart. In the following example, the options Length and MinPart are combined together to obtain the list of the compositions of 4 with 3 nonnegative parts:

combinat::compositions(4, Length=3, MinPart=0)

If no length is given, MinPart=0 is not allowed.

Parameters

n

Nonnegative integer

Options

MinPart

Option, specified as MinPart = k

Return only compositions consisting of integers greater or equal than k. The option MinPart = 0 is only allowed if also the option Length is given. Default is 1.

MaxPart

Option, specified as MaxPart = l

Return only compositions consisting of integers less or equal than l.

Length

Option, specified as Length = m

Return only compositions consisting of exactly m integers.

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