How can I select the smallest value from the subset of a subset?

Question

I have a dataframe with three columns: Batch, Trial, Time.

Five Trials (0-4) are ran for each Batch number.

I want to pull out the row with the smallest time from each Batch and put them into a new dataframe.

I'm not sure where to start.

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See this one too: [how to efficiently select rows with minimum value in R?](http://stackoverflow.com/questions/13499430/how-to-efficiently-select-rows-with-minimum-value-in-r) — Backlin, Oct 23 '13 at 07:04

score 0 · Accepted Answer · answered Oct 23 '13 at 07:18

0

Assuming the dataframe as df.

Try
df.new <- df[ df$Time == ave(df$Time, df$Batch, FUN=min), ])

answered Oct 23 '13 at 07:18

Kumar

1 Answers1