codes for the paper

Yong Long and J. A. Fessler.
Multi-material decomposition using statistical image reconstruction for spectral CT. 
IEEE Trans. Med. Imag., 33(8):1614-26, Aug. 2014.

The codes need to be used with MIRT (http://web.eecs.umich.edu/~fessler/code/)
mmd_pl_decom.m: the proposed PL method 
mmd_true_object.m: generating the modified NCAT phantom in the paper