根据R中的四个条件计算两列值

我在r中上传了一个大数据集（见下面的简短版本）：我想为每个

Cruiseid

、

Samplenr

、

物种和
年龄计算一个值（因此基于四个条件）：

我想计算：
（（TNumStat$TNumLK/TNumStat$TNumStat）*0.5+0.25）*10
每个
Cruiseid
，
samplener
，
物种
和
年龄

我已经在循环构造中尝试了一些东西：

#######################
Cruise <- unique(TNumStat$Cruiseid)
Track <- unique(TNumStat$Samplenr)
#######################
AvrLengthCr <- c()
AvrLengthCr <- rep(NA, length(TNumStat$Species))
#######################
for(j in 1:length(Cruise)){
  t1.ss <- which(TNumStat$Cruiseid ==  Cruise[j])
  ###
  for(i in 1:length(Track)){
    t2.ss <- which(TNumStat$Samplenr[t1.ss] ==  Track[i])
    ###
    AvrLengthCr[t1.ss][t2.ss] <- ((TNumStat$TNumLK[t1.ss][t2.ss]/TNumStat$TNumStat[t1.ss][t2.ss])*0.5+0.25)*10
  }}

#######################
克鲁斯早上好

在我看来，这个问题并不完全清楚。但您可以尝试（使用dplyr）

sample%
变异（计算=（（TNumLK/TNumStat）*0.5+0.25）*10）%>%
分组依据（Cruiseid、Samplenr、物种、年龄）
汇总DF%
总结（平均计算=平均值（计算））
让我印象深刻的是您的列
“Length”、“TNumStat”、“TNumLK”
有
，
而不是
，因此它们是字符格式，无法如此轻松地强制转换为数字

TNumStat[c("TNumStat", "TNumLK")] <- 
  lapply(TNumStat[c("TNumStat", "TNumLK")], 
         function(x) as.numeric(gsub(",", ".", x)))

这将为您提供一个列表，您可以
rbind
获取结果

TNumStat.new <- do.call(rbind, l)

TNumStat.new
#    Cruiseid Samplenr Species     value
# 6    197502       35     154 148.46288
# 10   197502       36     154  85.14956
# 1    197502       37     154 149.61421
# 12   197502       41     154 174.24600
# 26   197503       53     154 106.86347
# 20   197503       54     154 159.17545
# 16   197503       56     154 131.26698

TNumStat.new是否需要
库（dplyr）；df%>%groupby（Cruiseid，samplerr，Species，Age）%>%mutate（比率=（（TNumLK/TNumStat）*0.5+0.25）*10）
？你可能必须先用
TNumStat[c（“TNumStat”，“TNumLK”）]@jay.sf清理你的数据。为什么它现在不工作？这些数字现在不正确吗？如果你不介意的话，考虑接受回答或者投票。是的，但我可以按“向上”按钮吗？：/。。。所以我把它做成了绿色！啊，因为你还没有15个名声。既然您现在有了它们，它现在应该可以工作了。：）完成！谢谢你的帮助！
sample <- sample %>%
  mutate(calculate = ((TNumLK/TNumStat) * 0.5 + 0.25) * 10) %>%
  group_by(Cruiseid, Samplenr, Species, Age)

summarisedDF <- sample %>%
  summarise(avg.calculate = mean(calculate))

TNumStat[c("TNumStat", "TNumLK")] <- 
  lapply(TNumStat[c("TNumStat", "TNumLK")], 
         function(x) as.numeric(gsub(",", ".", x)))

l <- by(TNumStat, TNumStat[c("Cruiseid", "Samplenr", "Species")],
        function(x) cbind(unique(x[1:3]),
                          value=with(x, ((mean(TNumLK)/mean(TNumStat))*0.5+0.25)*10)))

TNumStat.new <- do.call(rbind, l)

TNumStat.new
#    Cruiseid Samplenr Species     value
# 6    197502       35     154 148.46288
# 10   197502       36     154  85.14956
# 1    197502       37     154 149.61421
# 12   197502       41     154 174.24600
# 26   197503       53     154 106.86347
# 20   197503       54     154 159.17545
# 16   197503       56     154 131.26698

TNumStat <- structure(list(Cruiseid = c(197502L, 197502L, 197502L, 197502L, 
197502L, 197502L, 197502L, 197502L, 197502L, 197502L, 197502L, 
197502L, 197502L, 197502L, 197502L, 197503L, 197503L, 197503L, 
197503L, 197503L, 197503L, 197503L, 197503L, 197503L, 197503L, 
197503L, 197503L, 197503L, 197503L), Samplenr = c(37L, 37L, 37L, 
37L, 37L, 35L, 35L, 35L, 35L, 36L, 36L, 41L, 41L, 41L, 41L, 56L, 
56L, 56L, 56L, 54L, 54L, 54L, 54L, 54L, 54L, 53L, 53L, 53L, 53L
), Species = c(154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 
154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 
154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L, 154L), 
    Age = c(0L, 0L, 2L, 2L, 2L, 0L, 2L, 2L, 2L, 0L, 2L, 0L, 2L, 
    2L, 2L, 0L, 0L, 2L, 2L, 0L, 0L, 0L, 2L, 2L, 2L, 0L, 0L, 0L, 
    0L), Length = structure(c(3L, 8L, 9L, 10L, 11L, 2L, 13L, 
    16L, 17L, 3L, 11L, 8L, 14L, 15L, 18L, 8L, 5L, 9L, 12L, 3L, 
    6L, 7L, 9L, 12L, 16L, 3L, 19L, 1L, 4L), .Label = c("107,5", 
    "112,5", "12,5", "142,5", "147,5", "157,5", "167,5", "17,5", 
    "172,5", "177,5", "182,5", "187,5", "197,5", "202,5", "212,5", 
    "217,5", "232,5", "242,5", "97,5"), class = "factor"), LK = c(2L, 
    3L, 34L, 35L, 36L, 22L, 39L, 43L, 46L, 2L, 36L, 3L, 40L, 
    42L, 48L, 3L, 29L, 34L, 37L, 2L, 31L, 33L, 34L, 37L, 43L, 
    2L, 19L, 21L, 28L), TNumStat = structure(c(16L, 11L, 2L, 
    5L, 9L, 3L, 10L, 10L, 10L, 21L, 19L, 13L, 20L, 12L, 12L, 
    24L, 1L, 6L, 14L, 18L, 4L, 7L, 8L, 15L, 15L, 17L, 22L, 23L, 
    25L), .Label = c("10,30952381", "11,54166667", "11,85654008", 
    "12", "12,0625", "13,19047619", "13,25", "13,85", "2,083333333", 
    "2,109704641", "2,166666667", "2,173913043", "2,260869565", 
    "2,380952381", "2,5", "2,791666667", "2,875536481", "3,35", 
    "3,496503497", "4,347826087", "4,685314685", "4,806866953", 
    "5,622317597", "7,428571429", "8,776824034"), class = "factor"), 
    TNumLK = structure(c(16L, 18L, 11L, 12L, 21L, 8L, 22L, 25L, 
    29L, 24L, 4L, 20L, 5L, 26L, 1L, 6L, 9L, 14L, 23L, 19L, 10L, 
    13L, 15L, 28L, 2L, 17L, 27L, 3L, 7L), .Label = c("104,3478", 
    "107,5", "118,0687", "125,8741", "173,913", "22,28571", "245,7511", 
    "260,8439", "298,9762", "372", "392,4167", "422,1875", "437,25", 
    "448,4762", "470,9", "5,583333", "5,751073", "6,5", "6,7", 
    "6,782609", "75", "82,27848", "88,09524", "9,370629", "90,7173", 
    "91,30435", "91,33047", "92,5", "97,04641"), class = "factor")), class = "data.frame", row.names = c(NA, 
-29L))