[R] Finding Highest value in groups

[Tom Wright]

Assuming your dataframe is in a variable x:

> require(dplyr)
> x %>% group_by(ID) %>% summarise(maxVal = max(Value,na.rm=TRUE))



On Fri, 2016-04-22 at 13:51 +0000, Saba Sehrish via R-help wrote:
> Hi
> 
> 
> I have two columns in data frame. First column is based on "ID" assigned to each group of my data (similar ID depicts one group). From second column, I want to identify highest value among each group and want to assign the same ID to that highest value.
> 
> Right now the data looks like:
> 
> ID    Value
> 1        0.69
> 1        0.31
> 2        0.01
> 2        0.99
> 3        1.00
> 4        NA
> 4        0
> 4        1
> 5        0.5
> 5        0.5
> 
> I want to use R program to get results as below:
> 
> ID       Value
> 1        0.69
> 2        0.99
> 3        1.00
> 4        1
> 5        0.5
> 
> Kindly guide me in this regard.
> 
> Thanks
> Saba
> 
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