search for: mariannestephan

Hello, How can I apply a function on a vector that refers to actual (n) and previous elements in the vector (e.g. n-1)? For example: I would like to calculate the sum of (n-1) + n for each element of a vector and get a vector as a result. Besides others I tried this: v<-c(3,6,8,1,1,3,9,5,6,3) for (i in 1:NROW(v)){a[i]<-a[i-1]+a[i]} I would like to get this result:

Dear R and statistics experts: I have data of a behavioral experiment with the aim to investigate the effect of a memory task on motor learning. Question: I would appreciate help in figuring out a possible formula to determine whether motor learning across sessions differs between 2 groups. Design: - 2 Groups: group A: n=10 subjects, group B: n=10 - 6 motor learning sessions: baseline;

Hello everybody, A statistician performed an analysis in SAS for me which I would like to replicate in R. I have however problems in figuring out the R code to do that. As I understood it was a "covariance regression model". In the analysis, baseline was used as covariate and autoregressive (1) as covariance structure. The model included baseline, session, group and interaction