# anas2mat.m

Converts anisotropy and asymmatry representation of a 3x3 interaction tensor into the corresponding matrix.

## Syntax

    M=anas2mat(iso,an,as,alp,bet,gam)


## Description

Isotropic part, anisotropy, and asymmetry are often seen in the literature. It is not a good way of reporting an interaction tensor (the original matrix is best), but it is still being used.

## Arguments

       iso  - isotropic part of the interaction, defined as
(xx+yy+zz)/3 in terms of eigenvaues

an  - interaction anisotropy, defined as zz-(xx+yy)/2
in terms of eigenvalues

as  - interaction asymmetry, defined as (yy-xx)/(zz-iso)
in terms of eigenvalues

alp  - alpha Euler angle in radians

bet  - beta Euler angle in radians

gam  - gamma Euler angle in radians


## Outputs

    M  - 3x3 matrix


## Notes

The reverse transformation (from matrix into anisotropy, asymmetry, and angles) is ill-defined.