Multinomial

Multinomial[n1,n2,]

gives the multinomial coefficient .

Details

  • Integer mathematical function, suitable for both symbolic and numerical manipulation.
  • The multinomial coefficient Multinomial[n1,n2,], denoted , gives the number of ways of partitioning distinct objects into sets, each of size (with ).
  • Multinomial automatically threads over lists.

Examples

open allclose all

Basic Examples  (5)

Evaluate numerically:

The 1, 2, 1 multinomial coefficient appears as the coefficient of x y^2 z:

Plot over a subset of the reals:

Plot over a subset of the complexes:

Series expansion at the origin:

Series expansion at Infinity:

Scope  (18)

Numerical Evaluation  (4)

Evaluate numerically:

Evaluate to high precision:

The precision of the output tracks the precision of the input:

Complex number input:

Evaluate efficiently at high precision:

Specific Values  (4)

Values of Multinomial at fixed points:

Multinomial for symbolic n:

Values at zero:

Find a value of n for which Multinomial[n,1,1]=15:

Visualization  (2)

Plot the Multinomial as a function of its parameter:

Plot the real part of 6 TemplateBox[{{x, +, {ⅈ,  , y}, +, 6}, {x, +, {ⅈ,  , y}}}, Binomial]:

Plot the imaginary part of 6 TemplateBox[{{x, +, {ⅈ,  , y}, +, 6}, {x, +, {ⅈ,  , y}}}, Binomial]:

Function Properties  (4)

The real domain of Multinomial as a function of its last parameter n:

The complex domain:

Approximate function range of Multinomial:

Multinomial has the mirror property:

TraditionalForm formatting:

Differentiation  (2)

The first derivative with respect to n3:

Higher derivatives with respect to n3:

Plot the higher derivatives with respect to n3 when n1=n2=3:

Series Expansions  (2)

Find the Taylor expansion using Series:

Plots of the first three approximations around :

The Taylor expansion at a generic point:

Generalizations & Extensions  (1)

Multinomial threads elementwise over lists:

Applications  (4)

Illustrate the multinomial theorem:

Plot isosurfaces of the number of ways to put elements in three boxes:

Multinomial probability distribution:

Volume of a hyper-super-ellipsoid is :

Compare with direct integration:

Properties & Relations  (4)

With two arguments, Multinomial gives binomial coefficients:

Use FullSimplify to simplify expressions involving multinomial coefficients:

Use FunctionExpand to expand into Gamma functions:

Multinomial is Orderless:

Possible Issues  (3)

Large arguments can give results too large to be computed explicitly:

Machine-number inputs can give highprecision results:

As a multivariate function, Multinomial is not continuous in all variables at negative integers:

Neat Examples  (3)

Trinomials mod 2:

Modulo 3:

Nested multinomials over the complex plane:

Plot Multinomial for complex arguments:

Introduced in 1988
 (1.0)