library(dyplr)
library(reshape2)

# Convert a dataframe in long format to wide format when we have more than 1 IV factor

# Original data frame "df" in long format
# We have one dependent variable (dv) and two independent variables (iv1, iv2)
# as separate columns.

df_group_summary <- df %>%
  group_by(id, iv1, iv2) %>%
  summarise(mean(dv))

#Reshape
wide_group_summary <- dcast(df_group_summary, id ~ iv1 + iv2)
write_csv(wide_group_summary, "/path/wide_group_summary.csv")