I don't know what equation best fits the line. I think that the curve for some of my data looks like a power function. Since I don't know the exponent, I used the custom model for nonlinear regression. I need an R2 and AICc values to compare different models. I created a column using the power equation and then went to analyze to modeling to nonlinear and put in my y values and then put in the power equation column into the predictor column. I then pushed go to calculate the parameters. However, I can't get an R2 or AICc value or a p value. I also have used the built in logistic 3p regression fit, but there are some outliers that are skewing the curve. I would like to be able to adjust the curve to better fit my data. How do I do this? Please help me. I have read all the jmp help sections on nonlinear regression and even watched some youtube videos, but I still can't figure it out. If anyone knows how to do this, please let me know,