R根据条件对名称进行排序

Question

I'm trying to put group names together order them, while letting the position of the other names depends on the order mentioned above above.

Let's say I have the following names

 a <- c("zz", "CountryA", "CountryC", "xy", "aa","CountryB")

and I want to order the Country together to give the following output.

c("zz", "CountryA", "CountryB", "CountryC", "xy", "aa")

I got the results above from the following function.

orderGroup <- function(regex,char) {
### purpose
     ## order by group leaving the rest unchanged
    group <- grep(regex,char,value=TRUE)
    orderGroup <- group[order(group)]

    indexGroup <-  grep(regex,char)
    indexNotInGroup <-  grep(paste0("^[^",regex,"]"),char)

    c(char[indexNotInGroup[indexNotInGroup<min(indexGroup)]],
      orderGroup,char[indexNotInGroup[indexNotInGroup>min(orderc)]])
 }

usage:

orderGroup("Country",a)

From this point I have 1 question:

• Do you have a better way of doing this. I have not tested the function except on the above so I'm sure there are cases to add and some tuning to do.

Answer 1

This seems to work:

patt = "^Country"

cs = grep(patt, a)
append(a[-cs], sort(a[cs]), after = cs[1]-1)
# "zz"       "CountryA" "CountryB" "CountryC" "xy"       "aa" 

It is not substantially different from the OP's function, though.