计算给定条件的百分比
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【中文标题】计算给定条件的百分比【英文标题】：Calculate percentage given condition 【发布时间】：2018-07-22 00:39:21 【问题描述】：我是这个网站的新手，也是编码新手。我想知道你们中是否有人可以帮助我
我需要通过评分分布计算前 5 部电影，计算每部电影评分为 4 星或更高的百分比。
到目前为止，我只能使用 dplyr 计算出现次数。
是否可以使用 dplyr（类似于我的编码）来计算它？
我不确定我是否需要变异来提出解决方案，或者是否有其他方法。
到目前为止我的代码：
dfAux1 <- na.omit(dfAux)
dfAux1 %>%
group_by(movie) %>%
summarise(tot = n()) %>%
arrange(desc(tot))%>%
head(5)
结果应该是这样的：
**Expected result**:
0.7000000, 'The Shawshank Redemption'
0.5333333, 'Star Wars IV - A New Hope'
0.5000000, 'Gladiator'
0.4444444, 'Blade Runner'
0.4375000, 'The Silence of the Lambs'
到目前为止，这是我的结果：
# A tibble: 5 x 2
movie tot
<fctr> <int>
1 Toy Story 17
2 The Silence of the Lambs 16
3 Star Wars IV - A New Hope 15
4 Star Wars VI - Return of the Jedi 14
5 Independence Day 13
编辑：
str(dfAux1)
'data.frame': 241 obs. of 2 variables:
$ Rating: int 1 5 4 2 4 5 4 2 3 2 ...
$ movie : Factor w/ 20 levels "Star Wars IV - A New Hope",..: 1 1 1 1 1 1 1 1 1 1 ...
- attr(*, "na.action")=Class 'omit' Named int [1:159] 3 4 7 16 17 23 27 28 34 36 ...
.. ..- attr(*, "names")= chr [1:159] "3" "4" "7" "16" ...
dput(dfAux1)
structure(list(Rating = c(1L, 5L, 4L, 2L, 4L, 5L, 4L, 2L, 3L,
2L, 3L, 4L, 4L, 5L, 1L, 5L, 3L, 3L, 3L, 4L, 1L, 2L, 1L, 5L, 3L,
4L, 5L, 1L, 2L, 2L, 4L, 4L, 3L, 5L, 2L, 3L, 1L, 1L, 2L, 2L, 5L,
1L, 4L, 1L, 4L, 5L, 5L, 5L, 4L, 4L, 4L, 2L, 4L, 1L, 3L, 2L, 3L,
2L, 4L, 2L, 5L, 3L, 4L, 1L, 5L, 4L, 2L, 1L, 1L, 4L, 2L, 4L, 5L,
5L, 2L, 1L, 4L, 2L, 1L, 4L, 2L, 3L, 2L, 4L, 4L, 5L, 2L, 4L, 3L,
2L, 2L, 4L, 2L, 2L, 2L, 3L, 4L, 1L, 5L, 4L, 3L, 5L, 2L, 1L, 3L,
4L, 4L, 2L, 3L, 4L, 1L, 3L, 2L, 5L, 3L, 2L, 3L, 4L, 1L, 1L, 4L,
1L, 4L, 5L, 1L, 3L, 2L, 2L, 3L, 5L, 5L, 1L, 2L, 3L, 5L, 2L, 3L,
1L, 2L, 1L, 4L, 1L, 2L, 2L, 3L, 3L, 2L, 1L, 1L, 1L, 5L, 2L, 4L,
1L, 4L, 3L, 1L, 2L, 2L, 3L, 4L, 2L, 3L, 2L, 4L, 3L, 4L, 3L, 2L,
2L, 4L, 5L, 2L, 1L, 5L, 1L, 4L, 5L, 2L, 3L, 3L, 2L, 5L, 5L, 4L,
1L, 3L, 1L, 2L, 1L, 5L, 5L, 2L, 4L, 2L, 4L, 2L, 5L, 2L, 5L, 5L,
1L, 5L, 1L, 3L, 2L, 2L, 3L, 5L, 1L, 3L, 1L, 5L, 3L, 3L, 1L, 2L,
4L, 1L, 5L, 3L, 1L, 1L, 5L, 5L, 1L, 5L, 3L, 3L, 2L, 3L, 3L, 2L,
2L, 2L, 5L, 4L, 2L, 1L, 4L, 5L), movie = structure(c(1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L,
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L,
3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 5L,
5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 6L,
6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 7L, 7L, 7L, 7L, 7L,
7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 8L, 8L, 8L, 8L,
8L, 8L, 8L, 8L, 8L, 8L, 8L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L,
9L, 9L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L,
11L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 12L, 12L,
12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 13L, 13L, 13L,
13L, 13L, 13L, 13L, 13L, 13L, 13L, 13L, 13L, 13L, 14L, 14L, 14L,
14L, 14L, 14L, 14L, 14L, 14L, 15L, 15L, 15L, 15L, 15L, 15L, 15L,
15L, 15L, 15L, 15L, 15L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L,
16L, 16L, 16L, 16L, 17L, 17L, 17L, 17L, 17L, 17L, 17L, 17L, 17L,
17L, 17L, 17L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L,
18L, 18L, 19L, 19L, 19L, 19L, 19L, 19L, 19L, 19L, 19L, 19L, 19L,
20L, 20L, 20L, 20L, 20L, 20L, 20L, 20L, 20L, 20L), .Label = c("Star Wars IV - A New Hope",
"Star Wars VI - Return of the Jedi", "Forrest Gump", "The Shawshank Redemption",
"The Silence of the Lambs", "Gladiator", "Toy Story", "Saving Private Ryan",
"Pulp Fiction", "Stand by Me", "Shakespeare in Love", "Total Recall",
"Independence Day", "Blade Runner", "Groundhog Day", "The Matrix",
"Schindler's List", "The Sixth Sense", "Raiders of the Lost Ark",
"Babe"), class = "factor")), .Names = c("Rating", "movie"), row.names = c(1L,
2L, 5L, 6L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 18L, 19L, 20L,
21L, 22L, 24L, 25L, 26L, 29L, 30L, 31L, 32L, 33L, 35L, 38L, 39L,
40L, 41L, 45L, 46L, 47L, 51L, 52L, 54L, 56L, 58L, 60L, 62L, 63L,
65L, 66L, 67L, 69L, 70L, 73L, 78L, 80L, 81L, 82L, 83L, 85L, 87L,
88L, 89L, 90L, 92L, 93L, 94L, 95L, 96L, 97L, 98L, 100L, 101L,
102L, 104L, 105L, 107L, 108L, 109L, 111L, 115L, 116L, 118L, 119L,
121L, 122L, 123L, 124L, 126L, 128L, 129L, 130L, 131L, 132L, 133L,
134L, 135L, 137L, 138L, 139L, 140L, 141L, 144L, 145L, 146L, 147L,
149L, 150L, 153L, 156L, 159L, 160L, 164L, 166L, 167L, 168L, 170L,
172L, 175L, 177L, 178L, 179L, 180L, 181L, 182L, 183L, 185L, 186L,
189L, 194L, 195L, 196L, 199L, 200L, 201L, 202L, 205L, 206L, 207L,
209L, 212L, 216L, 217L, 219L, 220L, 222L, 223L, 224L, 225L, 226L,
228L, 229L, 231L, 233L, 234L, 235L, 239L, 241L, 242L, 243L, 244L,
246L, 248L, 249L, 250L, 251L, 252L, 253L, 254L, 255L, 261L, 263L,
264L, 265L, 267L, 268L, 274L, 278L, 280L, 282L, 283L, 284L, 286L,
288L, 289L, 292L, 293L, 294L, 295L, 296L, 300L, 301L, 303L, 305L,
307L, 310L, 311L, 312L, 314L, 316L, 317L, 319L, 320L, 321L, 322L,
323L, 324L, 325L, 328L, 330L, 334L, 335L, 336L, 338L, 340L, 341L,
342L, 343L, 344L, 345L, 346L, 348L, 350L, 351L, 356L, 358L, 360L,
362L, 363L, 364L, 367L, 368L, 371L, 373L, 375L, 376L, 378L, 380L,
383L, 384L, 386L, 387L, 389L, 391L, 392L, 395L, 396L, 398L), class = "data.frame", na.action = structure(c(3L,
4L, 7L, 16L, 17L, 23L, 27L, 28L, 34L, 36L, 37L, 42L, 43L, 44L,
48L, 49L, 50L, 53L, 55L, 57L, 59L, 61L, 64L, 68L, 71L, 72L, 74L,
75L, 76L, 77L, 79L, 84L, 86L, 91L, 99L, 103L, 106L, 110L, 112L,
113L, 114L, 117L, 120L, 125L, 127L, 136L, 142L, 143L, 148L, 151L,
152L, 154L, 155L, 157L, 158L, 161L, 162L, 163L, 165L, 169L, 171L,
173L, 174L, 176L, 184L, 187L, 188L, 190L, 191L, 192L, 193L, 197L,
198L, 203L, 204L, 208L, 210L, 211L, 213L, 214L, 215L, 218L, 221L,
227L, 230L, 232L, 236L, 237L, 238L, 240L, 245L, 247L, 256L, 257L,
258L, 259L, 260L, 262L, 266L, 269L, 270L, 271L, 272L, 273L, 275L,
276L, 277L, 279L, 281L, 285L, 287L, 290L, 291L, 297L, 298L, 299L,
302L, 304L, 306L, 308L, 309L, 313L, 315L, 318L, 326L, 327L, 329L,
331L, 332L, 333L, 337L, 339L, 347L, 349L, 352L, 353L, 354L, 355L,
357L, 359L, 361L, 365L, 366L, 369L, 370L, 372L, 374L, 377L, 379L,
381L, 382L, 385L, 388L, 390L, 393L, 394L, 397L, 399L, 400L), .Names = c("3",
"4", "7", "16", "17", "23", "27", "28", "34", "36", "37", "42",
"43", "44", "48", "49", "50", "53", "55", "57", "59", "61", "64",
"68", "71", "72", "74", "75", "76", "77", "79", "84", "86", "91",
"99", "103", "106", "110", "112", "113", "114", "117", "120",
"125", "127", "136", "142", "143", "148", "151", "152", "154",
"155", "157", "158", "161", "162", "163", "165", "169", "171",
"173", "174", "176", "184", "187", "188", "190", "191", "192",
"193", "197", "198", "203", "204", "208", "210", "211", "213",
"214", "215", "218", "221", "227", "230", "232", "236", "237",
"238", "240", "245", "247", "256", "257", "258", "259", "260",
"262", "266", "269", "270", "271", "272", "273", "275", "276",
"277", "279", "281", "285", "287", "290", "291", "297", "298",
"299", "302", "304", "306", "308", "309", "313", "315", "318",
"326", "327", "329", "331", "332", "333", "337", "339", "347",
"349", "352", "353", "354", "355", "357", "359", "361", "365",
"366", "369", "370", "372", "374", "377", "379", "381", "382",
"385", "388", "390", "393", "394", "397", "399", "400"), class = "omit"))
【问题讨论】：
请dput 分享包含电影细节的数据框。
您应该使用dput(dfAux1) 并分享输出。 str 帮助不大。
我做了，看起来很糟糕嘿嘿
谢谢。看看我使用data.table 的单行解决方案。
【参考方案1】：
我使用的是data.table 而不是dplyr
library(data.table)
setDT(dfAux1) # make dfAux1 as data table by reference
# calculate total number by movies, then compute percent for `Rating >= 4` by movies and then sort `tot` by descending order and also eliminating duplicates in movies using `.SD[1]` which gives the first row in each movie.
dfAux1[, .(Rating, tot = .N), by = movie ][Rating >= 4, .(percent = .N/tot, tot), by = movie ][order(-tot), .SD[1], by = movie]
# movie percent tot
# 1: Toy Story 0.35294118 17
# 2: The Silence of the Lambs 0.43750000 16
# 3: Star Wars IV - A New Hope 0.53333333 15
# 4: Star Wars VI - Return of the Jedi 0.35714286 14
# 5: Independence Day 0.30769231 13
# 6: Gladiator 0.50000000 12
# 7: Total Recall 0.08333333 12
# 8: Groundhog Day 0.41666667 12
# 9: The Matrix 0.41666667 12
# 10: Schindler's List 0.33333333 12
# 11: The Sixth Sense 0.33333333 12
# 12: Saving Private Ryan 0.36363636 11
# 13: Pulp Fiction 0.36363636 11
# 14: Stand by Me 0.36363636 11
# 15: Shakespeare in Love 0.27272727 11
# 16: Raiders of the Lost Ark 0.27272727 11
# 17: Forrest Gump 0.30000000 10
# 18: The Shawshank Redemption 0.70000000 10
# 19: Babe 0.40000000 10
# 20: Blade Runner 0.44444444 9
【讨论】：
这并不是我想要做的，例如，Gladiator 有 12 条评论，在这 12 条评论中，有 6 条被评为 4 或 5，因此我要寻找的数字是 50%。 它有效！谢谢，我只需要按前 5 名订购【参考方案2】：概述
我使用dplyr 包将您的数据按movie 列分组，并根据rating 列执行计算。
在summarise() 中，我创建了三个新列：
Total_Review：统计每个movie的评论总数。
FourPlus_Rating：计算 Rating 值为 4 或更高的评论子集。
Per_FourPlus_Rating：将FourPlus_Rating 除以Total_Review。
然后我根据Per_FourPlus_Rating 按降序排列日期。最后，我调用head() 指定我只希望tibble 返回前5 行。
可重现的示例
# install necessary package
install.packages( pkgs = "dplyr" )
# load necessary package
library( dplyr )
# view first six rows
head( x = df )
# Rating movie
# 1 1 Star Wars IV - A New Hope
# 2 5 Star Wars IV - A New Hope
# 5 4 Star Wars IV - A New Hope
# 6 2 Star Wars IV - A New Hope
# 8 4 Star Wars IV - A New Hope
# 9 5 Star Wars IV - A New Hope
# perform calculations using
# dplyr functions
df %>%
group_by( movie ) %>%
summarise( Total_Review = n()
, FourPlus_Rating = length( Rating[ which( Rating >= 4 ) ] )
, Per_FourPlus_Rating = length( Rating[ which( Rating >= 4 ) ] ) / n() ) %>%
arrange( desc( Per_FourPlus_Rating ) ) %>%
head( n = 5 )
# A tibble: 5 x 4
# movie Total_Review FourPlus_Rating Per_FourPlus_Rati…
# <fct> <int> <int> <dbl>
# 1 The Shawshank Rede… 10 7 0.700
# 2 Star Wars IV - A N… 15 8 0.533
# 3 Gladiator 12 6 0.500
# 4 Blade Runner 9 4 0.444
# 5 The Silence of the… 16 7 0.438
# end of script #
【讨论】：
我认为它应该是你所做的事情（至少我正在寻找），唯一的问题是我需要计算出现次数而不是求和。例如，角斗士有 12 条评论，其中 6 条的评分 >=4，应该得到 0.5 哦，你修好了，谢谢！它有效，无法弄清楚它的长度......我非常感谢你帮助我 感谢您分享所需的输出！我在上面添加了一些解释。希望这会有所帮助！ 感谢您的精彩解释。可能您可以删除df 的定义，并且该定义已包含在 OP 本身中。这将使您的帖子非常清晰易懂。
感谢@MKR！我没有意识到它看起来有多丑哈哈现在干净多了！【参考方案3】：
使用data.table 和来自 OP 的数据的单行解决方案可能如下：
library(data.table)
setDT(dfAux1)[, .(pct = sum(Rating>=4)/.N), by=movie][order(-pct)][1:5]
movie pct
1: The Shawshank Redemption 0.7000000
2: Star Wars IV - A New Hope 0.5333333
3: Gladiator 0.5000000
4: Blade Runner 0.4444444
5: The Silence of the Lambs 0.4375000
【讨论】：
谢谢！不知道我是高兴还是生气你只用一行代码就能做到这一点呵呵【参考方案4】：这是一个 dplyr 解决方案：
dfAuxhigh=filter(dfAux1,Rating>=4)%>%group_by(movie)%>%summarize(percentHigh=n())
dfAux=dfAux1%>%group_by(movie)%>%summarize(percentAll=n())
result<-merge(dfAuxhigh,dfAux,by="movie")%>%mutate(percentage=percentHigh/percentAll)
result<-result[order(result$percentage,decreasing = T)[1:5],c(1,4)]
【讨论】：
【参考方案5】：library(tidyverse)
df %>%
group_by(movie, Rating) %>%
summarise(n = n()) %>% #< get freq of movies
mutate(freq = n/sum(n)) %>% #< find perc for each rating, by movie
filter(Rating >=4) %>% #< filter for desired rating (4 or above)
summarise(freq = sum(freq)) %>% #< summarize again
top_n(5) %>%
arrange(desc(freq)) %>%
mutate(freq = paste0(round(freq*100, 2), "%"))
#> movie freq
#> 1 The Shawshank Redemption 70%
#> 2 Star Wars IV - A New Hope 53.33%
#> 3 Gladiator 50%
#> 4 Blade Runner 44.44%
#> 5 The Silence of the Lambs 43.75%
【讨论】：
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