Question

我是R的新手，在下面需要帮助。我有此数据：

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我需要创建一个数据框“ minute_data”。每行对应一分钟的观测值，其中包含该分钟内的事件计数和温度。

某些分钟可能不包含任何事件。与此类分钟对应的行应从数据框中排除。

数据框应该看起来像（前2行）：

  Time Temperature
  4.460672    96.32332
 15.542545    96.32332
 16.750386    96.32332
 38.709795    96.32332
 39.952442    96.32332
 41.320898    96.32332
 55.375259    96.32332
 61.855321   100.47791
 66.464590   100.47791
 66.966965   100.47791
 76.100513   100.47791
 76.617365   100.47791
 77.186545   100.47791
 83.032157   100.47791
 87.772441   100.47791
 91.786988   100.47791
 98.161933   100.47791
101.258411   100.47791
105.186097   100.47791
105.928643   100.47791
111.476967   100.47791
119.426046   100.47791
124.406232    92.70218
135.352858    92.70218
136.545958    92.70218

Answer 1

您可以使用dplyr：

library(dplyr)
df %>%
  mutate(minute = Time %/% 60 + 1) %>%
  group_by(minute) %>%
  summarise(count = n(),
            temperature = first(temperature)) %>%
  select(-Time)

注意：如果您想要卑鄙的话，请将first更改为mean

Answer 2

（当然）data.table也可以执行此操作

样本数据

library( data.table )
DT <- fread("Time Temperature
4.460672    96.32332
15.542545    96.32332
16.750386    96.32332
38.709795    96.32332
39.952442    96.32332
41.320898    96.32332
55.375259    96.32332
61.855321   100.47791
66.464590   100.47791
66.966965   100.47791
76.100513   100.47791
76.617365   100.47791
77.186545   100.47791
83.032157   100.47791
87.772441   100.47791
91.786988   100.47791
98.161933   100.47791
101.258411   100.47791
105.186097   100.47791
105.928643   100.47791
111.476967   100.47791
119.426046   100.47791
124.406232    92.70218
135.352858    92.70218
136.545958    92.70218")

代码

这实际上是单行代码，但是出于可读性考虑，我添加了一些换行符。

DT[, list( count = .N, 
           temperature = mean( Temperature ) ), 
   by = .( minute = floor( Time / 60 ) + 1 )]

输出

#    minute count temperature
# 1:      1     7    96.32332
# 2:      2    15   100.47791
# 3:      3     3    92.70218

r中的分组时间戳数据

2 个答案: