我想从数据框中删除一行并对结果列求和。我知道我要根据其内容删除的行,但不知道它的行号。下面我介绍三个示例,其中两个有效。仅在要删除第一行时使用-
删除行。这是为什么?
我的问题与此类似:如何删除 R 中数据框的第一行? 但是,该行会根据其行号被删除。
# This works.
state = 'OH'
my.data = read.table(text = "
county y1990 y2000
cc NA 2
OH NA 10
bb NA 1
", sep = "", header = TRUE, na.strings = "NA", stringsAsFactors = FALSE)
my.colsums2 <- colSums(my.data[!(my.data$county == state), 2:ncol(my.data)], na.rm=TRUE)
my.colsums2
# y1990 y2000
# 0 3
# This works.
my.data = read.table(text = "
county y1990 y2000
OH NA 10
cc NA 2
bb NA 1
", sep = "", header = TRUE, na.strings = "NA", stringsAsFactors = FALSE)
my.colsums2 <- colSums(my.data[-(my.data$county == state), 2:ncol(my.data)], na.rm=TRUE)
my.colsums2
# y1990 y2000
# 0 3
# This does not work.
my.data = read.table(text = "
county y1990 y2000
cc NA 2
OH NA 10
bb NA 1
", sep = "", header = TRUE, na.strings = "NA", stringsAsFactors = FALSE)
my.colsums2 <- colSums(my.data[-(my.data$county == state), 2:ncol(my.data)], na.rm=TRUE)
my.colsums2
# y1990 y2000
# 0 11
我想我仍然对 和 之间的区别感到!
困惑-
。谢谢你的任何建议。