CODEWITHSUNDEEP
rsumaggregate
Fairy
Fairy

Reputation: 389

conditional replacement of a value for a column of a specific row of a data frame with sum of specific rows

I have been struggling with aggregation/sum in R for my data frame. My data is as follows:

    hour    Case   Time
       7       2    35
       8       8    125
       9       10   145
       10      15   18
       11      17   167
       12      20   220
       13      25   135
       14      14   167
       15      18   134
       16      16   100
       17      7    55
       18      6    178
       19      5    245
       20      1    133
       21      1    12
       22      0    54
       23      2    180
       24      1    55

I simply want to replace the "case" and Time" values for row where "hour"==8 with sum of "case" and "Time" values for rows where "hour" <= 8 or "hours" > 18 . I tried conditional aggregate(), with(), colsums() functions in R but none of them worked. I wonder if anybody can give me a hint.

Thanks

Upvotes: 2

Views: 255

Answers (1)

David Arenburg
David Arenburg

Reputation: 92282

You could try conditional colSums while assigning by condition to your original data set

df[df$hour == 8, c("Case", "Time")] <- colSums(df[df$hour <= 8 | df$hour > 18, c("Case", "Time")])

Upvotes: 3

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