R:在具有重复项的数据框上传播函数

Question

我有一个需要转换的数据框，但该数据框具有重复的标识符，因此 spread 函数给出错误 错误:行 (5、6) 的重复标识符

Dimension = c("A","A","B","B","A","A")   
Date = c("Mon","Tue","Mon","Wed","Fri","Fri")    
Metric = c(23,25,7,9,7,8)
df = data.frame(Dimension,Date,Metric)
df

  Dimension Date Metric
1         A  Mon     23
2         A  Tue     25
3         B  Mon      7
4         B  Wed      9
5         A  Fri      7
6         A  Fri      8

library(tidyr)
df1 = spread(df, Date, Metric, fill = " ")

Error: Duplicate identifiers for rows (5, 6)

然后我合并了行并粘贴了Metric:

dfa = aggregate(df[3], df[-3], 
                FUN = function(X) paste(unique(X), collapse=", "))

  Dimension Date Metric
1         A  Fri   7, 8
2         A  Mon     23
3         B  Mon      7
4         A  Tue     25
5         B  Wed      9

然后重复，当然现在可以了:

df1 = spread(dfa, Date, Metric, fill = " ")
df1
  Dimension  Fri Mon Tue Wed
1         A 7, 8  23  25    
2         B        7       9

问题:是否有一种“更简单”的方法可以做到这一点，或者我的上述方法是否足够有效，所以我不需要为此失眠？谢谢!

编辑。所有代码——我的和 2 个 akrun 的代码都可以很好地处理这个小数据集。但是，akrun 的 dplyr 版本在我的真实数据集上出现问题。这是dput。

structure(list(Dimension = c(10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 10994030020, 10994030020, 10994030020, 10994030020, 
10994030020, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12300245685, 12300245685, 12300245685, 12300245685, 12300245685, 
12303485675, 12303485675, 12303485675, 12303485675, 12303485675, 
12701670437, 12701670437, 12701670437, 12701670437, 12701670437, 
12701670437, 12701670437, 12701670437, 12701670437, 12701670437, 
12701670437, 12701670437, 12701670437, 12701670437, 12701670437, 
12701670437), Date = structure(c(1L, 3L, 5L, 7L, 9L, 10L, 11L, 
12L, 13L, 14L, 16L, 18L, 19L, 20L, 22L, 23L, 24L, 26L, 27L, 28L, 
30L, 32L, 33L, 34L, 40L, 41L, 42L, 47L, 48L, 49L, 51L, 52L, 53L, 
54L, 55L, 58L, 59L, 60L, 61L, 62L, 63L, 65L, 66L, 68L, 69L, 70L, 
74L, 75L, 76L, 2L, 3L, 5L, 7L, 8L, 10L, 11L, 15L, 17L, 20L, 21L, 
24L, 25L, 28L, 30L, 31L, 34L, 36L, 42L, 43L, 46L, 48L, 49L, 53L, 
54L, 56L, 65L, 67L, 68L, 69L, 70L, 71L, 72L, 73L, 7L, 24L, 30L, 
38L, 65L, 4L, 6L, 7L, 24L, 28L, 29L, 30L, 35L, 37L, 39L, 44L, 
45L, 50L, 57L, 64L, 65L), .Label = c("16", "analog tuner", "aspect ratio", 
"assembled in country of origin", "backlight technology", "battery type", 
"brand", "brightness", "color class", "component video", "composite video", 
"country of origin", "depth w/ stand", "digital audio output", 
"digital tuner", "display technology", "features", "green compliance certificate/authority", 
"green compliant", "hdmi", "headphone jack", "height w/ stand", 
"limited warranty", "manufacturer", "maximum resolution", "media player", 
"motion interpolation technology", "mpn", "multi pack indicator", 
"name", "native contrast ratio", "number of hdmi ports", "number of usb ports", 
"operating power consumption", "origin of components", "package contents", 
"primary color", "product dimensions", "product in in (l x w x h)", 
"product model", "product series", "product type", "remote control incl", 
"remote included", "resolution", "response time", "rms output power", 
"scan format", "screen size", "shipping weight (in lb)", "sound system", 
"speaker output power (w)", "speakers", "standard refresh rate", 
"standby power consumption", "total number of hdmi ports", "tv definition", 
"tv features", "tv refresh rate (hz)", "tv resolution", "tv screen size (in)", 
"tv screen size range", "tv speakers", "tv technology", "unspsc", 
"usb", "vertical viewing angle", "vesa mount standard", "vga", 
"video signal standard", "viewing angle", "warranty length", 
"wattage", "weight (approx)", "weight w/ stand (approx)", "width w/ stand"
), class = "factor"), Metric = structure(c(40L, 13L, 57L, 69L, 
43L, 72L, 72L, 45L, 38L, 72L, 55L, 44L, 72L, 72L, 15L, 3L, 69L, 
72L, 46L, 26L, 70L, 27L, 1L, 29L, 26L, 54L, 58L, 12L, 39L, 25L, 
42L, 11L, 72L, 37L, 28L, 52L, 36L, 39L, 24L, 19L, 72L, 33L, 72L, 
18L, 72L, 49L, 6L, 10L, 23L, 62L, 13L, 48L, 64L, 31L, 72L, 72L, 
41L, 66L, 72L, 72L, 64L, 16L, 63L, 65L, 4L, 32L, 21L, 58L, 71L, 
35L, 8L, 20L, 72L, 37L, 17L, 33L, 14L, 7L, 72L, 50L, 14L, 2L, 
34L, 59L, 59L, 60L, 5L, 33L, 51L, 47L, 67L, 67L, 53L, 61L, 68L, 
51L, 43L, 30L, 72L, 9L, 22L, 49L, 56L, 33L), .Label = c("1", 
"1-year limited", "1 Year", "1,000:1", "1,140 x 145 x 705 in ; 65.6 lb", 
"10.40 lb", "100 x 100", "1080p", "1080p (HDTV)", "11.20 lb", 
"14", "14 W", "16:9", "178 degrees", "18.30 in", "1920 x 1080", 
"2", "200 x 100", "21", "22 in", "22 in FHD LED TV; Remote Control", 
"25.4", "26.20 in", "29", "29 in", "29L1350U", "3", "300 mW", 
"33.80 W", "36.5 x 6.5 x 23.0", "365 Nit", "50 W", "52161505", 
"6 W", "6.50 ms", "60", "60 Hz", "7.10 in", "720p", "9", "ATSC", 
"Audyssey EQ", "Black", "CEC", "China", "ClearScan 120 Hz", "Does Not Contain a Battery", 
"Edge LED", "HDTV", "HDTV 1080p", "Imported", "Internet Apps", 
"KDL40W600B", "L1350U", "LCD", "LCD, Internet Connected, LED", 
"LED", "LED-LCD TV", "LG", "LG 47LY340C - 47 in - commercial use LED-backlit L", 
"No", "NTSC", "PLED2243A", "ProScan", "PROSCAN PLED2243A 22 in 1080p 60 Hz LED HDTV - PTR", 
"Sleep Timer; Auto Program", "Sony", "Sony KDL40W600B 40 in 1080p 60 Hz Smart LED TV (20", 
"Toshiba", "Toshiba 29L1350U 29 in 720p LED-LCD TV - 16:9 - HD", 
"yes", "Yes"), class = "factor")), .Names = c("Dimension", "Date", 
"Metric"), class = c("data.table", "data.frame"), row.names = c(NA, 
-104L), .internal.selfref = <pointer: 0x00000000003d0788>)

Answer 1

您可以使用 data.table 的开发版本中的 dcast 即。 v1.9.5。安装说明是here

library(data.table)#v1.9.5+
dcast(setDT(df), Dimension~Date, value.var='Metric', 
               fun.aggregate=function(x) toString(unique(x)))
#   Dimension  Fri Mon Tue Wed
#1:         A 7, 8  23  25    
#2:         B        7       9

或者

library(dplyr)
library(tidyr)
df %>%
   group_by(Dimension, Date) %>% 
   summarise(Metric=toString(unique(Metric))) %>% 
   spread(Date, Metric, fill='')
#   Dimension  Fri Mon Tue Wed
#1         A 7, 8  23  25    
#2         B        7       9

更新

使用来自“OP 的帖子”的新数据集

 setDF(df2)
 df2 %>% 
     group_by(Dimension, Date) %>% 
     summarise(Metric=toString(unique(Metric))) %>%
     spread(Date, Metric, fill='') %>%
     head(2) %>%
     select(1:3)
 #    Dimension 16 analog tuner
 #1 10994030020  9             
 #2 12300245685            NTSC