我正在尝试根据适用于各种条件的数据对数据进行分类。条件之一是日期时间（m / d / y hh：mm）。分类应在白天/夜晚进行，即白天的时间为07：00/19：00，晚上的时间为19：01/06：59，并且还应基于季节，即m / d / y。是否可以创建基于多个条件（例如数值数据-温度，湿度，因子-“强风”，“中风”和日期时间）进行分类的新变量。
这是我的数据结构。
$ T : int 11 11 13 13 14 16 17 17 18 18 ...
$ P0 : num 700 699 700 699 699 ...
$ P : num 764 763 763 763 762 ...
$ U : int 54 58 47 47 41 36 34 37 34 34 ...
$ DD : Factor w/ 18 levels "","Calm","Wind
blowing from the east",..: 17 17 9 17 9 9 9 9 9 10
...
$ Ff : int 5 3 4 4 4 5 4 6 7 7 ...
$ ff10 : int NA NA NA NA NA NA NA NA 11 10 ...
$ WW : Factor w/ 3 levels "","In the vicinity
thunderstorm",..: 1 1 1 1 1 1 1 1 1 1 ...
$ W.W. : logi NA NA NA NA NA NA ...
$ c : Factor w/ 245 levels "Broken clouds (60-
90%) 1020 m",..: 32 154 86 86 151 154 216 124 86 86
...
$ VV : num 16 16 NA NA 16 16 16 16 16 16 ...
$ Td : int 2 3 NA NA 1 1 1 2 2 2 ...
$ datetime: chr "9/30/14 23:00" "9/30/14 22:00"
"9/30/14 21:00" "9/30/14 20:00" ...
$ T_g_5 : num 12.8 13.4 14.1 14.9 16 17.2 18 19.1
19.9 19.9 ...
$ T_g_20 : num 16.3 16.5 16.7 16.8 16.8 16.8 16.7
16.3 16 15.4 ...
$ T_g_35 : num 17.3 17.2 17.3 17.3 17.3 17 17.2 17
17 16.7 ...
$ T_g_50 : num 17.5 17.5 17.5 17.5 17.5 17.5 17.7
17.7 17.7 17.7 ...
$ T_g_75 : num 18.6 18.6 18.6 18.6 18.8 18.9 18.9
18.9 18.9 18.9 ...
$ s_m_5 : num 0.182 0.184 0.184 0.187 0.185 0.192
0.193 0.19 0.193 0.195 ...
$ s_m_20 : num 0.209 0.205 0.207 0.206 0.202 0.201
0.195 0.195 0.195 0.19 ...
$ s_m_35 : num 0.142 0.142 0.142 0.146 0.144 0.143
0.146 0.146 0.146 0.146 ...
$ s_m_50 : num 0.149 0.149 0.151 0.146 0.149 0.146
0.144 0.144 0.149 0.149 ...
$ s_m_75 : num 0.139 0.144 0.144 0.144 0.144 0.144
0.144 0.142 0.142 0.142 ...
我尝试使用以下代码对数据进行分类。
DF$pest[DF$T <= 15 & DF$T > 10 & DF$U >=50 & DF$U <
75 & DF$datetime >= "9/27/14 13:00" & DF$datetime <
"9/27/14 16:00" ] <- "Threat"
以下上面的代码在我的列有害生物中给出了“ NA”。还有其他方法可以对上述数据进行分类吗？谢谢。
dput输出
> dput(smalldata)
structure(list(X.x = 1:4, T = c(11L, 11L, 13L, 13L), P0 = c(699.6,
699.4, 699.6, 699.4), P = c(763.5, 763.3, 763, 762.8), U = c(54L,
58L, 47L, 47L), DD = structure(c(17L, 17L, 9L, 17L), .Label = c("",
"Calm", "Wind blowing from the east", "Wind blowing from the east-northeast",
"Wind blowing from the east-southeast", "Wind blowing from the north",
"Wind blowing from the north-east", "Wind blowing from the north-northeast",
"Wind blowing from the north-northwest", "Wind blowing from the north-west",
"Wind blowing from the south", "Wind blowing from the south-east",
"Wind blowing from the south-southeast", "Wind blowing from the south-southwest",
"Wind blowing from the south-west", "Wind blowing from the west",
"Wind blowing from the west-northwest", "Wind blowing from the west-southwest"
), class = "factor"), Ff = c(5L, 3L, 4L, 4L), ff10 = c(NA_integer_,
NA_integer_, NA_integer_, NA_integer_), WW = structure(c(1L,
1L, 1L, 1L), .Label = c("", "In the vicinity thunderstorm", "Thunderstorm"
), class = "factor"), W.W. = c(NA, NA, NA, NA), VV = c(16, 16,
NA, NA), Td = c(2L, 3L, NA, NA), datetime = c("9/30/14 23:00",
"9/30/14 22:00", "9/30/14 21:00", "9/30/14 20:00"), T_g_5 = c(12.8,
13.4, 14.1, 14.9), T_g_20 = c(16.3, 16.5, 16.7, 16.8), T_g_35 = c(17.3,
17.2, 17.3, 17.3), T_g_50 = c(17.5, 17.5, 17.5, 17.5), T_g_75 = c(18.6,
18.6, 18.6, 18.6), s_m_5 = c(0.182, 0.184, 0.184, 0.187), s_m_20 = c(0.209,
0.205, 0.207, 0.206), s_m_35 = c(0.142, 0.142, 0.142, 0.146),
s_m_50 = c(0.149, 0.149, 0.151, 0.146), s_m_75 = c(0.139,
0.144, 0.144, 0.144), X.y = c(NA, NA, NA, NA), pest = c(NA_character_,
NA_character_, NA_character_, NA_character_)), .Names = c("X.x",
"T", "P0", "P", "U", "DD", "Ff", "ff10", "WW", "W.W.", "VV",
"Td", "datetime", "T_g_5", "T_g_20", "T_g_35", "T_g_50", "T_g_75",
"s_m_5", "s_m_20", "s_m_35", "s_m_50", "s_m_75", "X.y", "pest"
), row.names = c(NA, 4L), class = "data.frame")
答案 0 :(得分：0)
尝试将其分解，然后您可以更轻松地发现问题所在。
也就是说，我可以立即看到一个问题：您的日期存储为character。
如果这样做，是否有效？
as.POSIXct(DF$datetime, format='%m/%d/%y %H:%M') >=
as.POSIXct("9/27/14 13:00", format='%m/%d/%y %H:%M')