CODEWITHSUNDEEP
r
63549
63549

Reputation: 95

If condition error in r

I have two variable a and b 

 A      B
 1      id
-1      asddnewid
13      asddsatransID 
-1      sadsddsdasd
-1      asdsadasdd

I want to find if a is > 0 then i want to search the variable B for character "transid" and get the index of it.

I tried the below code

if (a > 0) {
c = regexpr("transid=",B)
}

But it showing error. I am not sure whether iam writing the if condition properly

Upvotes: 1

Views: 86

Answers (1)

akrun
akrun

Reputation: 886938

We can use grep. If we need the index from only the positive values in "A"

 grep("transID", df1$B[df1$A>0])
 #[1] 2

If the index is based on all the rows

i1 <- which(df1$A >0 & grepl("transID", df1$B))
i1
#[1] 3
sapply(gregexpr("transID", df1$B[i1]), c)
#[1] 7

Or just

r1 <- sapply(gregexpr("transID", df1$B[df1$A > 0]), c)
r1[r1 >0]
#[1] 7

Regarding using if condition, if is not vectorized, so it may be good to use ifelse. However, from the OP's post, the a is not defined. I am assuming that the OP meant A.

data

df1 <- structure(list(A = c(1L, -1L, 13L, -1L, -1L), B = 
c("id", "asddnewid", 
"asddsatransID", "sadsddsdasd", "asdsadasdd")), .Names = c("A", 
"B"), class = "data.frame", row.names = c(NA, -5L))

Upvotes: 1

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