根据另一个数据框中的值有条件地替换一个数据框中的列名

时间:2019-11-23 00:21:35

标签: r for-loop names

我已经下载了流转移数据表(“ df_download”)。该表的列名主要取自计量站的ID号。

我想有条件地用站名文本替换列名使用的ID号,这将有助于在共享结果时使数据更易读。我创建了一个带有ID号和站名的表(“ stationID”),用作更改“ df_download”列名的参考。

我可以单独替换列名,但是我想编写某种循环,以解决“ df_download”的所有列并更改数据帧“ stationID”中引用的列的名称。

下面是我要尝试的示例。

下载的数据(“ df_download”)

部分下载的数据与此类似:

df_downloaded <- data.frame(Var1 = seq(as.Date("2012-01-01"),as.Date("2012-12-01"), by="month"),
                            Var2 = sample(50:150,12, replace =TRUE),
                            Var3 = sample(10:100,12, replace =TRUE),
                            Var4 = sample(15:45,12, replace =TRUE),
                            Var5 = sample(50:200,12, replace =TRUE),
                            Var6 = sample(15:100,12, replace =TRUE),
                            Var7 = c(rep(0,3),rep(13,6),rep(0,3)),
                            Var8 = rep(5,12))
colnames(df_downloaded) <- c("Diversion.Date","360410059","360410060",
                             "360410209","361000655","361000656","Irrigation","Seep") 

df_download # not run
# 
#    Diversion.Date 360410059 360410060 360410209 361000655 361000656 Irrigation Seep
# 1      2012-01-01        93        57        28       101        16          0    5
# 2      2012-02-01       102        68        19       124        98          0    5
# 3      2012-03-01       124        93        36       109        56          0    5
# 4      2012-04-01        94        96        23        54        87         13    5
# 5      2012-05-01        83        70        43       119        15         13    5
# 6      2012-06-01        78        63        45       195        15         13    5
# 7      2012-07-01        86        77        20       130        63         13    5
# 8      2012-08-01       118        29        27       118        57         13    5
# 9      2012-09-01       142        18        45       116        27         13    5
# 10     2012-10-01        74        68        34       182        79          0    5
# 11     2012-11-01       106        48        27        95        74          0    5
# 12     2012-12-01        91        41        20       179        55          0    5

参考表(“ stationID”)

stationIDs <- data.frame(ID = c("360410059", "360410060", "360410209", "361000655", "361000656"),
                         Names = c("RimView", "IPCO", "WMA.Ditch", "RV.Bypass", "LowerFalls"))
stationIDs # not run
#
#          ID      Names
# 1 360410059    RimView
# 2 360410060       IPCO
# 3 360410209  WMA.Ditch
# 4 361000655  RV.Bypass
# 5 361000656 LowerFalls

我可以使用单个语句替换“ df_downloaded”中的列名。我在下面显示前三个迭代。
经过三轮迭代后,“ RimValley”,“ IPCO”和“ WMA.Ditch”已替换了它们各自的仪表ID号。

names(df_downloaded) <- gsub(stationIDs$ID[1],stationIDs$Name[1],names(df_downloaded))

# head(df_downloaded)
#   Diversion.Date RimView 360410060 360410209 361000655 361000656 Irrigation Seep
# 1     2012-01-01      93        57        28       101        16          0    5
# 2     2012-02-01     102        68        19       124        98          0    5
# 3     2012-03-01     124        93        36       109        56          0    5
# 4     2012-04-01      94        96        23        54        87         13    5
# 5     2012-05-01      83        70        43       119        15         13    5
# 6     2012-06-01      78        63        45       195        15         13    5

names(df_downloaded) <- gsub(stationIDs$ID[2],stationIDs$Name[2],names(df_downloaded))

# head(df_downloaded)
#   Diversion.Date RimView IPCO 360410209 361000655 361000656 Irrigation Seep
# 1     2012-01-01      93   57        28       101        16          0    5
# 2     2012-02-01     102   68        19       124        98          0    5
# 3     2012-03-01     124   93        36       109        56          0    5
# 4     2012-04-01      94   96        23        54        87         13    5
# 5     2012-05-01      83   70        43       119        15         13    5
# 6     2012-06-01      78   63        45       195        15         13    5

names(df_downloaded) <- gsub(stationIDs$ID[3],stationIDs$Name[3],names(df_downloaded))

# head(df_downloaded)
#   Diversion.Date RimView IPCO WMA.Ditch 361000655 361000656 Irrigation Seep
# 1     2012-01-01      93   57        28       101        16          0    5
# 2     2012-02-01     102   68        19       124        98          0    5
# 3     2012-03-01     124   93        36       109        56          0    5
# 4     2012-04-01      94   96        23        54        87         13    5
# 5     2012-05-01      83   70        43       119        15         13    5
# 6     2012-06-01      78   63        45       195        15         13    5

如果我尝试使用for循环进行重命名,则会以NA结束列名。

for(i in seq_along(names(df_downloaded))){
    names(df_downloaded) <- gsub(stationIDs$ID[i],stationIDs$Name[i],names(df_downloaded))
}

# head(df_downloaded)
#           NA  NA NA NA  NA NA NA NA
# 1 2012-01-01  93 57 28 101 16  0  5
# 2 2012-02-01 102 68 19 124 98  0  5
# 3 2012-03-01 124 93 36 109 56  0  5
# 4 2012-04-01  94 96 23  54 87 13  5
# 5 2012-05-01  83 70 43 119 15 13  5
# 6 2012-06-01  78 63 45 195 15 13  5

我真的希望能够使用for循环或类似名称来更改名称,因为因为我从中下载数据的站点数量会根据我所分析的年份而变化。

感谢您抽出时间来看我的问题。

2 个答案:

答案 0 :(得分:1)

我们可以使用match

#Convert factor columns to character
stationIDs[] <- lapply(stationIDs, as.character)
#Match names of df_downloaded with stationIDs$ID
inds <- match(names(df_downloaded), stationIDs$ID)
#Replace the matched name with corresponding Names from stationIDs
names(df_downloaded)[which(!is.na(inds))] <- stationIDs$Names[inds[!is.na(inds)]]

df_downloaded
#   Diversion.Date RimView IPCO WMA.Ditch RV.Bypass LowerFalls Irrigation Seep
#1      2012-01-01     142   14        41       200         79          0    5
#2      2012-02-01      97  100        35       176         22          0    5
#3      2012-03-01      85   59        26        88         71          0    5
#4      2012-04-01      68   49        34        63         15         13    5
#5      2012-05-01      62   58        44        87         16         13    5
#6      2012-06-01      70   59        33       145         87         13    5
#7      2012-07-01     112   65        25        52         64         13    5
#8      2012-08-01      75   12        27       103         19         13    5
#9      2012-09-01      73   65        36       172         68         13    5
#10     2012-10-01      87   35        27       146         42          0    5
#11     2012-11-01     122   17        33       183         32          0    5
#12     2012-12-01     108   65        15       120         99          0    5

答案 1 :(得分:0)

您可以执行dplyr和tidyr。基本上,您希望使数据变长,以便将ID放在一列中,以便您可以使用ID对名称的引用对此进行连接。然后,您可以再次将数据范围扩大。

df_downloaded %>%
   gather(ID, value, -Diversion.Date, -Irrigation, -Seep) %>% 
   left_join(., stationIDs) %>%
   dplyr::select(-ID) %>% 
   spread(Names, value)