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

## Description

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

## Usage

 `1` ```convert.mpoly(poly) ```

## Arguments

 `poly` an mpoly 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 'mpoly', it is a list with two components shown below. If poly is such a list, the value is the corresponding mpoly object

## Author(s)

Kem Phillips <kemphillips@comcast.net>

## 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``` ```# create an mpoly object here # convert from mpoly to list representation 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))) t1 <- convert.mpoly(t0) # convert from list representation back to an mpoly object t2 <- convert.mpoly(t1) ```