在日期范围内并基于 R 中另一列的值将数据框的某些列的值相乘

Question

我正在为 R 中的 ifelse 语句而苦苦挣扎。我有一个包含 64 列和 12861 行的数据框。我需要在一个日期范围内（日期是一列）和基于另一行（tdiff）中的值相乘这些列中的 10 个，并将旧值替换为数据框中的新值。这行代码生成一个 12681 X 12681 的数据帧。它应该是 12681（行）乘 64（列）的原始大小。我究竟做错了什么？提前谢谢！

test<-data.frame(ifelse(slopejoin$tdiff==2 & slopejoin$date>="2021-01-30" & slopejoin$date<="2021-08-08",
     slopejoin[,c("a_Pinene","Isoprene","Methyl_Vinyl_Ketone","Nopinone","Benzene_", "D_Limonene",
                  "Sabinene","a_Cedrene","Pentane","Hexane")]*0.85,
     slopejoin[,c("a_Pinene","Isoprene","Methyl_Vinyl_Ketone", "Nopinone","Benzene_", "D_Limonene",
                  "Sabinene","a_Cedrene","Pentane","Hexane")]))

编辑：我接受了第一个评论者的建议，但想再添加一个条件，但收到一个错误：“cols & slopejoin$substr 中的错误！= z： 只能对数字、逻辑或复杂类型进行操作。”这是我正在使用的代码：

cols <- c("a_Pinene","Isoprene","Methyl_Vinyl_Ketone", "Nopinone","Benzene_", "D_Limonene", "Sabinene","a_Cedrene","Pentane","Hexane")
x <- "2021-01-06"
y <- "2021-08-08"
z <- 'zero_VOC_2'

slopejoin[slopejoin$tdiff == 2 & slopejoin$date >= x & slopejoin$date <= y,cols & slopejoin$substr != z] <- slopejoin[slopejoin$tdiff == 2 & slopejoin$date >= x & slopejoin$date <= y,cols & slopejoin$substr != z] * 0.06

不太清楚错误来自哪里。首先我在考虑一个类问题，但似乎所有条件都用字符类检查。我尝试将“zero_VOC_2”的所有实例更改为 as.numeric(1) 或 TRUE 并检查条件中的那些但无济于事。感谢任何帮助！

Answer 1

cols <- "a_Pinene","Isoprene","Methyl_Vinyl_Ketone", "Nopinone","Benzene_", "D_Limonene", "Sabinene","a_Cedrene","Pentane","Hexane")
x <- "2021-01-30"
y <- "2021-08-08"

# Replace values in original fields
slopejoin[slopejoin$tdiff == 2 & slopejoin$date >= x & slopejoin$date <= y,cols] <- slopejoin[slopejoin$tdiff == 2 & slopejoin$date >= x & slopejoin$date <= y,cols] * 0.85