Hello,   I have a difficulty to get variables' value from other two variables. I have three continuous variables: x1, x2, x3.  x2=mean(x1)*(1-x1**2); x3=(mean(x1)+mean(x2))*(1-x2**2).   Here mean(x1) is the mean of all x1 values, the same as mean(x2). If I use the formula directly in data step, then mean(x1) will equal the current value of x1, not the mean of all x1 values. Is there one can help me figure out how to get the correct values of x2 and x3? Thanks a lot!   Rosie  ... View more

I saw the previous thread about pseudo-R2 formula for PROC NLIN: https://communities.sas.com/t5/Statistical-Procedures/nlin-goodness-of-fit/td-p/71273   Is there anyone knowing a literature about this pseudo R2 formula "pseudoR2 = 1 - (SSerror/SStotal(corrected))"? I couldn't find the provenance of this formula. There are several different pseudo R2s, such as McFadden’s R2, Efron’s R2, . McKelvey & Zavoina’s R2.  @Rick_SAS, @SteveDenham, @lvm, do you know a good reference of the formula? My regression is not a logit or probit regression. This is my linear model  proc nlin data=one method=marquardt; P=0.85; parms b0=95 b1=.19 xp=20.0; model cumgerm = b0 / (1 + ((1-P)/P) * exp(-b1*(gdd-xP))); * output out=A1 p=pred r=resid; run; Thanks very much!   Update: Sorry, no need about the reference. The formula is just a regular R2 for linear model.  However, is there any other Pseudo R2 can be obtained based on results from PROC NLIN? I know some of them based on loglikelihood, or for nominal response, so not sure which one can be used for continuous response and continuous explanatory variables like in my model.   Thanks!!  ... View more