Taking a Subset
We can subset a dataframe using index. For example we can subset specific columns and rows by following codes.
# column subset (subset df to only include column A and C) df[:, [:A, :C]] # row subset (subset df to only include 1st, 3rd, and 5th rows) df[[1,3,5], :]
We could also use some selectors such as
All. Following code removes columns whose names match
# add two columns x1 and x2 to df df[:, :x1].=0 df[:, :x2].=1 # subset columns whose names match "x" df[:, r"x"] # subset columns whose names do not match "x" df[:, Not(r"x")] # subset columns that are not A df[:, Not(:A)][1:10, :]
We could use
subset function to subset a dataframe.
# subset df where it looks at column A # to screen through observations whose values are less than 10 subset(df, :A=>a-> a .<10)