Filtering a data frame by values in a column

r filter dataframe
user722224 picture user722224 · Sep 11, 2011 · Viewed 450.6k times · Source

I am working with the dataset LearnBayes. For those that want to see the actual data: 

install.packages('LearnBayes')

I am trying to filter out rows based on the value in the columns. For example, if the column value is "water", then I want that row. If the column value is "milk", then I don't want it. Ultimately, I am trying to filter out all individuals who's Drink column is "water".

Answer

adamleerich picture adamleerich · Sep 12, 2011

The subset command is not necessary. Just use data frame indexing

studentdata[studentdata$Drink == 'water',]

Read the warning from ?subset

This is a convenience function intended for use interactively. For programming it is better to use the standard subsetting functions like ‘[’, and in particular the non-standard evaluation of argument ‘subset’ can have unanticipated consequences.

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