search for: rankits

Hello, My name is Lisa and I'm a statistician at Princess Margare Hospital. I wonder if there is any function in R that calculate the Normal rankits based on Blom's approximation? Thank you very much Lisa Wang Msc. Princess Margaret hospital Toronto, Ca

...lidation. Although there is no R code for this, the author informs me that it should be easy: 1. Calculate the linear predictor xb from the proportional hazards model or other model of interest. 2. Calculate the ranks r1,...,rn of xb. In case of ties, do not average the ranks. 3. Calculate scaled rankits zi = sqrt(_pi/8) * invnormal((ri - 3/8)/(n +1/4)) where invnormal() is the inverse normal distribution function, and where n is the sample size and _pi = 3.141592654 ... 4. In case of ties in the original xb, substitute average zi's over each of the tied sets. 5. Perform regression (e.g. Cox) o...

Hello R friends, I'm wondering why I get funny qqnorm() results. It seems that they should all be reflected in the normal qqline(). For instance: if I qqnorm() bimodal or uniform data I get a sigmoidal in which the qqnorm() points lie above the qqline() at -ve theoretical quantiles, and the qqnorm() points lie below the qqline() at +ve theoretical quantiles. Yet I expect such platykurtic