Question

我有两个csv文件：

文件1：

SN  CY  Year    Month   Day Hour    Lat Lon
196101  1   1961    1   14  12  8.3 134.7
196101  1   1961    1   14  18  8.8 133.4
196101  1   1961    1   15  0   9.1 132.5
196101  1   1961    1   15  6   9.3 132.2
196101  1   1961    1   15  12  9.5 132
196101  1   1961    1   15  18  9.9 131.8

file2的：

Year    Month Day RR Hour Lat  Lon
1961    1   14  0   0   14.0917 121.055
1961    1   14  0   6   14.0917 121.055
1961    1   14  0   12  14.0917 121.055
1961    1   14  0   18  14.0917 121.055
1961    1   15  0   0   14.0917 121.055
1961    1   15  0   6   14.0917 121.055

我想在file2中添加另一列并放入＆＃34; TRUE＆＃34;如果file2中的行存在于file1中，只要它们具有相同的年，月，日和小时，否则＆＃34; FALSE＆＃34;。然后另存为csv文件。

所需的输出：

Year    Month Day RR Hour Lat  Lon      com
1961    1   14  0   0   14.0917 121.055 FALSE
1961    1   14  0   6   14.0917 121.055 FALSE
1961    1   14  0   12  14.0917 121.055 TRUE
1961    1   14  0   18  14.0917 121.055 TRUE
1961    1   15  0   0   14.0917 121.055 TRUE
1961    1   15  0   6   14.0917 121.055 TRUE

这是我的剧本：

jtwc <- read.csv("file1.csv",header=T,sep=",")
stn <- read.csv("file2.csv",header=T,sep=",")

if ((jtwc$Year == "stn$YY") & (jtwc$Month == "stn$MM") & (jtwc$Day == "stn$DD") &(jtwc$Hour == "stn$HH")){
stn$com <- "TRUE"
} else {
stn$com <- "FALSE"
}
write.csv(stn,file="test.csv",row.names=T)

这会出错：

In if ((jtwc$Year == "stn$YY") & (jtwc$Month == "stn$MM") & (jtwc$Day ==  :the condition has length > 1 and only the first element will be used

Answer 1

您也可以使用dplyr / tidyverse：

library(tidyverse)
d2 %>% 
  left_join(select(d1, Year, Month, Day, Hour, Com=Lon)) %>% 
  mutate(Com=ifelse(is.na(Com), FALSE, TRUE))

Joining, by = c("Year", "Month", "Day", "Hour")
  Year Month Day RR Hour     Lat     Lon   Com
1 1961     1  14  0    0 14.0917 121.055 FALSE
2 1961     1  14  0    6 14.0917 121.055 FALSE
3 1961     1  14  0   12 14.0917 121.055  TRUE
4 1961     1  14  0   18 14.0917 121.055  TRUE
5 1961     1  15  0    0 14.0917 121.055  TRUE
6 1961     1  15  0    6 14.0917 121.055  TRUE

Answer 2

使用data.table快速而肮脏的解决方案：

使用fread读取文件。
从file1中提取所需的列（因为您只对file2感兴趣）
使用merge
如果file1添加FALSE

代码：

library(data.table)
result <- merge(fread("file2.csv"),
                fread("file1.csv")[, .(Year, Month, Day, Hour, com = TRUE)], 
                all.x = TRUE)[is.na(com), com := FALSE]

result
   Year Month Day Hour RR     Lat     Lon   com
1: 1961     1  14    0  0 14.0917 121.055 FALSE
2: 1961     1  14    6  0 14.0917 121.055 FALSE
3: 1961     1  14   12  0 14.0917 121.055  TRUE
4: 1961     1  14   18  0 14.0917 121.055  TRUE
5: 1961     1  15    0  0 14.0917 121.055  TRUE
6: 1961     1  15    6  0 14.0917 121.055  TRUE

根据常用列

2 个答案: