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rfor-looplag

R - for loop - using values in previous row

create a new column in R, using timepoints corresponding to a rating in another column.

Solution

  • Tidyverse solution: 

    install.packages("dplyr", dependencies = TRUE)
library(dplyr)
dataframe.df %>% 
  as.data.frame() %>% 
  mutate(Timepoint = as.numeric(gsub("[a-zA-Z]+", "", Timepoint))) %>% 
  group_by(Replicate, Stimulus, Subject) %>% 
  mutate(start_end_time = ifelse(Timepoint != max(Timepoint), min(Timepoint), max(Timepoint))) %>%
  ungroup()