我用SAS计算零膨胀负二项模型(zero inflated negative binomial model)：
proc nlmixed data=one;
parms j1=-3 j2=0.5 j3=-3
      k1=-2 k2=0.8 k3=-2.8 k4=-3.2 ;
mort=j1*A1+j2*Rs1+j3*H1;
pmort=1/(1+exp(-mort));
lamda=exp(k1+k2*Rs1+k3*Dm1+k4*Pw);
m=1/alpha ;
p=1/(1+alpha*lamda);
if y=0 then
     ll=log(pmort+(1-pmort)*(p**m));
else ll = log(1-pmort) + log(gamma(m + y)) - log(gamma(y + 1))
       - log(gamma(m)) + m*log(p) + y*log(1-p);
   model y ~ general(ll);out=pp;
run;

出现以下错误，能否帮忙解决下，谢谢了！

NOTE: Execution error for observation 48.
NOTE: PROCEDURE NLMIXED used (Total process time):
      real time           0.03 seconds
      cpu time            0.03 seconds