2016-11-09 161 views
0

假設我有大約180個不同的數據幀,這些數據幀看起來像這樣:列ID,x,it,st。現在我想更改st列,以便所有數據幀的新值爲st-1。因此,例如前9行中此數據幀的輸出仍爲NA,從第10行開始,它將是11.0。根據每個數據幀的列值更改多個數據幀的列

該數據幀例如被稱爲control37868.So列被改變爲control37868 $ ST

ID x   it   st 
2 1.464462e+12 20.17831 NA 
3 1.464462e+12 20.15657 NA 
4 1.464463e+12 20.13484 NA 
5 1.464463e+12 20.11310 NA 
6 1.464464e+12 20.09136 NA 
7 1.464465e+12 20.06963 NA 
8 1.464465e+12 20.04789 NA 
9 1.464466e+12 20.02615 NA 
10 1.464466e+12 20.00442 12.0 
11 1.464467e+12 19.98268 12.0 
12 1.464468e+12 19.96094 12.0 
13 1.464468e+12 19.93921 12.0 
14 1.464469e+12 19.95700 12.0 
15 1.464469e+12 20.01383 12.0 
16 1.464470e+12 19.96272 12.0 
17 1.464471e+12 19.96149 12.0 
18 1.464471e+12 20.01166 12.0 
19 1.464472e+12 19.92711 12.0 
20 1.464472e+12 19.90119 12.0 
21 1.464473e+12 19.88064 12.0 
22 1.464474e+12 19.86010 12.0 

我在它已經創造了所有dataframes列表:

#get list with all dataframes 
dflist <- list(incident11951, incident12720, incident13643, incident1379, incident14248, incident14968, incident15634, incident16439, incident17383, incident17734, incident17850, incident18009, incident18337, incident21888, incident22666, incident23269, incident23682, incident23870, incident24493, incident25116, incident25669, incident26222, incident26931, incident28226, incident28290, incident29070, incident29180, incident29484, incident29726, incident29969, incident30244, incident30691, incident30967, incident31376, incident31434, incident32608, incident33041, incident33668, incident35112, incident35254, incident35577, incident36125, incident36267, incident36592, incident36671, incident37244, incident37412, incident37724, incident37868, incident38161, incident39453, incident39786, incident40482, incident40487, incident40975, incident41013, incident41381, incident41701, incident41772, incident42226, incident42358, incident42613, incident43395, incident43476, incident44827, incident45053, incident45454, incident45605, incident45703, incident46637, incident47832, incident50133, incident52105, incident5585, incident56003, incident56862, incident58213, incident58960, incident617, incident6361, incident7122, incident8144, incident9027, incident9245, incident9262, incident9534, incident9875, control11951, control12720, control13643, control1379, control14248, control14968, control15634, control16439, control17383, control17734, control17850, control18009, control18337, control21888, control22666, control23269, control23682, control23870, control24493, control25116, control25669, control26222, control26931, control28226, control28290, control29070, control29180, control29484, control29726, control29969, control30244, control30691, control30967, control31376, control31434, control32608, control33041, control33668, control35112, control35254, control35577, control36125, control36267, control36592, control36671, control37244, control37412, control37724, control37868, control38161, control39453, control39786, control40482, control40487, control40975, control41013, control41381, control41701, control41772, control42226, control42358, control42613, control43395, control43476, control44827, control45053, control45454, control45605, control45703, control46637, control47832, control50133, control52105, control5585, control56003, control56862, control58213, control58960, control617, control6361, control7122, control8144, control9027, control9245, control9262, control9534, control9875) 

這應該是在dflist上使用sapply()函數可行,但我不確定如何定義根據當前值更改列值的正確函數。

只需添加該列並將其命名爲閾值即可。因此,我也試過

Map(cbind, dflist, threshold = st-1) 

但ST-1的基準是obviouly不足以做到這一點

回答

0

方式一:如果你想改變一個數據幀DF你可以

dflist<- lapply(dflist, function(x){ 
      y <- x[!is.na(x$st),]; 
      y$st <- y$st-1; 
      x[!is.na(x$st),] <- y; 
      x}) 

嘗試:

idx <- which(!is.na(df$st)) 
if (length(idx) > 0) df[idx, ]$st <- df[idx,]$st-1 
+0

也可以這樣做。 'lpply(l,function(x){y = x; y $ st < - y $ st-1; y})' –

+0

好;謝謝!這將該功能應用於具有數據框的列表。但是,當我現在調用單個數據框時,該列沒有更改。有沒有辦法將列表中的更改從數據框傳輸到實際的數據框? – GNee

+0

已更新,這是否回答了您的問題? –

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