I am using NLMIXED for Negative Binomial modeling with user defined functions. One of the models worked, but when I replaced a function from :
mu= 5*365*((MINAADT)**beta_1)* ((MAXAADT)**beta_2)*(EXP(beta_0))
with this:
5*365*(beta_0 + beta_1/((1+beta_2 *(MINAADT)**beta_3)*(1+beta_4*(MAXAADT)**beta_5)));
Following error is shown in the Log.
ERROR: QUANEW Optimization cannot be completed.
NOTE: QUANEW needs more than 200 iterations or 2000 function calls.
NOTE: PROCEDURE NLMIXED used (Total process time):
real time 0.19 seconds
cpu time 0.12 seconds
You didn't ask a question, but
1. If you are asking why the model didn't converge, the most likely reason is that the model does not fit the data and/or you did not provide a good initial guess for the parameters.
2. If you are asking what to do about it, then
2a. Make a better initial guess for parameters
2b. Change to a different optimize, such as TECH=NMSIMP or TECH=NRRIDG
2c.If you believe the model is almost converging, you can increase the number of iterations and the number of function evaluations that are permitted: MAXITER=500 MAXFUNC3000.
Don't miss out on SAS Innovate - Register now for the FREE Livestream!
Can't make it to Vegas? No problem! Watch our general sessions LIVE or on-demand starting April 17th. Hear from SAS execs, best-selling author Adam Grant, Hot Ones host Sean Evans, top tech journalist Kara Swisher, AI expert Cassie Kozyrkov, and the mind-blowing dance crew iLuminate! Plus, get access to over 20 breakout sessions.
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.
Find more tutorials on the SAS Users YouTube channel.