TITLE: Casselman-Shalika formula for split reductive groups
QUESTION [5 upvotes]: In the paper of Casselman and Shalika they give an explicit formula for the spherical Whittaker function of an unramified principal series.  Apparently, upon combining their formula with the Weyl character formula, one can get an evaluation of the Whittaker function in terms of the Satake parameter of the representation.  Can someone please explain how to do this, or give me a reference where it is done?

REPLY [2 votes]: I think something very close to what is asked in the original question is explained by Haines, Kottwitz and A. Prasad in their review article.