  In symmetric Macdonald polynomial theory the Pieri formula gives the
branching coefficients for the product of the rth elementary symmetric function
and the Macdonald polynomial. In this paper we give the nonsymmetric analogues
for the cases r=1 and r=n-1. We do this by first deducing the the decomposition
for the product of any nonsymmetric Macdonald polynomial with a linear function
in terms of nonsymmetric Macdonald polynomials. As a corollary of finding the
branching coefficients of the product of the first elementary function with a
nonsymmetric Macdonald polynomial we evaluate the generalised binomial
coefficients associated with the nonsymmetric Macdonald polynomials for
|u|=|v|+1.
