CODEWITHSUNDEEP
rdataframeminimum
cosmic_query
cosmic_query

Reputation: 1

In R how to find the first minimum value of a dataframe

How do I find the first minimum value in one column of a dataframe and output a new dataframe with just that row?

For example, for a dataframe named "hospital", for each node, I want to find the minimum time at which "H" is >=1.

node time H
1 1 0
2 1 0
3 1 0
1 2 0
2 2 0
3 2 2
1 3 0
2 3 1
3 3 2
1 4 1
2 4 4
3 4 0

The result I want to be able to output is:

node time H
1 4 1
2 3 1
3 2 2

Upvotes: 0

Views: 128

Answers (1)

Maël
Maël

Reputation: 52389

One way is to filter your dataframe, and then take the first minimum element for each group:

library(dplyr)
df %>% 
  filter(H > 0) %>% 
  group_by(node) %>% 
  slice_min(time, n = 1)

   node  time     H
  <int> <int> <int>
1     1     4     1
2     2     3     1
3     3     2     2

Upvotes: 1

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