Accessing and subsetting data frames (1)
Even more often than with vectors, you are going to want to subset your data frame or access certain columns. Again, one of the ways to do this is to use [ ]. The notation is just like matrices! Here are some examples:
Select the first row: cash[1, ]
Select the first column: cash[ ,1]
Select the first column by name: cash[ ,"company"]
Este exercicio faz parte do curso
Introduction to R for Finance
Instruções do exercicio
- Select the third row and second column of
cash. - Select the fifth row of the
"year"column ofcash.
exercicio interativo prático
Tente este exercicio completando este código de exemplo.
# Third row, second column
# Fifth row of the "year" column