# convert.multipol: Convert between multipol and list representations of... In symmoments: Symbolic central and noncentral moments of the multivariate normal distribution

## Description

Converts an multipol object to a simple list representing a multivariate polynomial or a simple list to an multipol object

## Usage

 `1` ```convert.multipol(poly) ```

## Arguments

 `poly` a multipol object or a list giving powers and coefficients defining the polynomial

## Details

The list representation consists of 2 components: 'powers' is a matrix with each row representing the powers of X in one term of the multivariate polynomial. 'coeff' is a vector with each element being the coefficient of the corresponding term in powers

## Value

if poly is of class 'multipol', it is a list with two components described below. If poly is such a list, the value is the corresponding multipol object

## Author(s)

Kem Phillips <[email protected]>

## References

K Phillips, Symbolic Computation of the Central Moments of the Multivariate Normal Distribution, Journal of Statistical Software, 2010.

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```# create an mpoly object to work with library(mpoly) t0 <- mpoly(list(c(coef=3,x1=2),c(coef=2,x1=1,x2=3), c(coef=-4,z=2),c(coef=1,x1=1,x2=2,z=1))) # convert from mpoly to list representation t1 <- convert.mpoly(t0) # convert from list representation to a multipol object t2 <- convert.multipol(t1) # convert back to a list representation t3 <- convert.multipol(t2) ```