如何用R中的条件语句替换行值

Question

I'm having 3 columns Seq, Period and Treatment. Sequence has values ABB,BBA,BAB,.. ie 1A and 2B combination. Period has 3 values ie 1,2 & 3 and Treatment will have value based on the Period and Sequence eg. if Sequence is ABB and Period is 1 then Treatment will be A if Sequence is ABB and Period is 2 then Treatment will be B similarly if Sequence is ABB and Period is 3 then Treatment will be B. following is the snapshot of the data

 Sequence Period Treatment   
    BBA      1         B  
    BBA      2         B  
    BBA      3         A 
    ABB      1         A 
    ABB      2         B 
    ABB      3         B

I want to Replace Treatment Value B of Sequence BBA and Period 1 with B1 and Sequence BBA and Period 2 with B2 similarly with the rest of the data.

I tried the following code

updatedata<-if((data$Sequence=='ABB' && data$Period==2) || (data$Sequence=='BAB' && data$Period==1) || (data$Sequence=='BBA' && data$Period==1)){
  data$Treatment<-'B1'
}else if((data$Sequence=='ABB' && data$Period==3) || (data$Sequence=='BAB' && data$Period==3) || (data$Sequence=='BBA' && data$Period==2)){
data$Treatment<-'B2'
}else((data$Sequence=='ABB' && data$Period==1) || (data$Sequence=='BAB' && data$Period==2) || (data$Sequence=='BBA' && data$Period==3)){
data$Treatment<-'A'}

I expect the following results

Sequence Period Treatment   
    BBA      1         B1  
    BBA      2         B2 
    BBA      3         A 
    ABB      1         A 
    ABB      2         B1
    ABB      3         B2

But I'm getting the following error:

Error: unexpected '{' in: " data$Treatment<-'B2' }else((data$Sequence=='ABB' && data$Period==1) || (data$Sequence=='BAB' && data$Period==2) || (data$Sequence=='BBA' && data$Period==3)){"

Answer 1

Using dplyr

z%>%mutate(Treatment=if_else(Treatment=="B",paste0("B",Period),Treatment))

1      BBA      1        B1
2      BBA      2        B2
3      BBA      3         A
4      ABB      1         A
5      ABB      2        B2
6      ABB      3        B3

Edit

Second version:

cond1 = z$Sequence=="BBA" & z$Treatment=="B"
cond2 = z$Sequence=="ABB" & z$Treatment=="B"
cond3 = z$Sequence=="BAB" & z$Treatment=="B"

z$Treatment[cond1]=paste0(z$Treatment[cond1],z$Period[cond1])
z$Treatment[cond2]=paste0(z$Treatment[cond2],z$Period[cond2]-1)
z$Treatment[cond3]=paste0(z$Treatment[cond3],
                          ifelse(z$Period[cond3]>2,2,1))
> z
   Sequence Period Treatment
2       BBA      1        B1
3       BBA      2        B2
4       BBA      3         A
5       ABB      1         A
6       ABB      2        B1
7       ABB      3        B2
8       BAB      1        B1
9       BAB      2         A
10      BAB      3        B2

data:

structure(list(Sequence = c("BBA", "BBA", "BBA", "ABB", "ABB", 
"ABB", "BAB", "BAB", "BAB"), Period = c(1, 2, 3, 1, 2, 3, 1, 
2, 3), Treatment = c("B1", "B2", "A", "A", "B1", "B2", "B1", 
"A", "B2")), row.names = 2:10, class = "data.frame")