小编Gra*_*ney的帖子

我是R的新手,我在网上找不到一个简单的例子,说明如何从向量的每个元素中删除最后n个字符(数组？)

我来自Java背景,所以我想做的是迭代每个元素a$data并从每个元素中删除最后3个字符.

你会怎么做？

我试图在R中的特定列周围创建边框.我能够使用kableExtra包(如下所示)

iris <- datasets::iris

iris2 <- do.call(data.frame, aggregate(. ~ Species, iris, function(x) c(mean = mean(x), sd = sd(x))))

res2 <- kable(iris2,"html", col.names =  c("Species", "Mean", "SD", "Mean", "SD", "Mean", "SD", "Mean", "SD"),   align = c("r","c","c","c","c","c","c","c","c")) %>%
  kable_styling(bootstrap_options = c("striped", "hover")) %>%
  add_header_above(c(" " = 1, "Sepal Length" = 2, "Sepal Width" = 2, "Petal Length" = 2, "Petal Width" = 2))

print(res2)

res3<- column_spec(res2, c(2,4,6,8), border_left = TRUE, border_right = FALSE)

column_spec(res3, c(3,5,7,9), border_left = FALSE, border_right = …

我有一个管道分隔字段的文件.我想打印字段1的子集和字段2的全部:

cat tmpfile.txt

# 10 chars.|variable length num|text
ABCDEFGHIJ|99|U|HOMEWORK
JIDVESDFXW|8|C|CHORES
DDFEXFEWEW|73|B|AFTER-HOURS

我希望输出看起来像这样:

# 6 chars.|variable length num
ABCDEF|99
JIDVES|8
DDFEXF|73

我知道如何获得字段1和2:

cat tmpfile.txt | awk '{FS="|"} {print $1"|"$2}'

并知道如何获得字段1的前6个字符:

cat tmpfile.txt | cut -c 1-6

我知道这很简单,但我无法弄清楚如何组合awk和cut命令.

任何建议将不胜感激.