如何将数据帧的两行合并为一行？

Question

基本上，我有一个简单的两列数据帧，一个以 10° 为间隔的圆度数，另一个在不同的数据帧中具有这些度数的频率。

In the degrees column there is a row for 0° and a row for 360°, and since those mean the same thing (in the context of wind direction) I'd like to combine the two rows into a single 0° row. E.g. from:

degree   freq 
0        1446
10       7652
20       2655
...
360      5417

To this

degree   freq 
0        6863
10       7652
20       2655
...

I'm sure this a very simple thing to do but I've spent 3 hours trying to figure it out and have gotten nowhere >.>

Answer 1

One option is to change the value of 360 to 0 and do a group by 'degree' and get the sum of 'freq'

library(dplyr)
df1 %>%
     group_by(degree = replace(degree, degree == 360, 0)) %>%
     summarise(freq = sum(freq))
# A tibble: 3 x 2
#  degree  freq
#*  <dbl> <int>
#1      0  6863
#2     10  7652
#3     20  2655

In base R, we can use aggregate

aggregate(freq ~ degree, transform(df1, 
      degree =  replace(degree, degree == 360, 0)), sum)

Or as @Onyambu commented

aggregate(freq~ degree %% 360,df1,sum)

NOTE: It is a generalized version where multiple elements with 360 can be changed to 0 and then do a group by sum

data

df1 <- structure(list(degree = c(0L, 10L, 20L, 360L), freq = c(1446L, 
7652L, 2655L, 5417L)), class = "data.frame", row.names = c(NA, 
-4L))