# [R] Help understanding loop behaviour

Jim Lemon drj|m|emon @end|ng |rom gm@||@com
Fri Apr 30 11:45:17 CEST 2021

```Hi email,
If you want what you described, try this:

0070837  3
0070837  3
0070837  3
1000403  4
1000403  4
1000403  4
1000403  4
10029943  3
10029943  3
10029943  3
10037980  4
10037980  4
10037980  4
10037980  4
10057418  3
10057418  3
10057418  3
1009550  4
1009550  4
1009550  4
1009550  4",
xx\$I<-NA
xx\$J<-NA
row_count<-1
for(row in 1:nrow(xx)) {
if(row == nrow(xx) || xx\$COMPANY_NUMBER[row]==xx\$COMPANY_NUMBER[row+1]) {
xx\$I[row]<-1
xx\$J[row]<-row_count
row_count<-row_count+1
} else {
xx\$I[row]<-xx\$J[row]<-xx\$NUMBER_OF_YEARS[row]
row_count<-1
}
}
xx

Like Petr, I am assuming that you want company 10057418 treated the
same as the others. If not, let us know why. I am also adssuming that
the first three rows should _not_ have a "#" at the beginning, which
means that they will be discarded.

Jim

On Fri, Apr 30, 2021 at 1:41 AM e-mail ma015k3113 via R-help
<r-help using r-project.org> wrote:
>
> I am trying to understand how loops in operate. I have a simple dataframe xx which is as follows
>
> COMPANY_NUMBER   NUMBER_OF_YEARS
>
> #0070837                             3
> #0070837                             3
> #0070837                             3
> 1000403                               4
> 1000403                               4
> 1000403                               4
> 1000403                               4
> 10029943                             3
> 10029943                             3
> 10029943                             3
> 10037980                             4
> 10037980                             4
> 10037980                             4
> 10037980                             4
> 10057418                             3
> 10057418                             3
>
> 10057418                             3
> 1009550                               4
> 1009550                               4
> 1009550                               4
> 1009550                               4
> The code I have written is
>
> while (i <= nrow(xx1) )
>
> {
>
> for (j in 1:xx1\$NUMBER_OF_YEARS[i])
> {
> xx1\$I[i] <- i
> xx1\$J[j] <- j
> xx1\$NUMBER_OF_YEARS_j[j] <- xx1\$NUMBER_OF_YEARS[j]
> }
> i=i + (xx1\$NUMBER_OF_YEARS[i] )
> }
> After running the code I want my dataframe to look like
>
> |COMPANY_NUMBER |NUMBER_OF_YEARS| | I| |J|
>
> |#0070837 |3| |1| |1|
> |#0070837 |3| |1| |2|
> |#0070837 |3| |3| |3|
> |1000403 |4| |1| |1|
> |1000403 |4| |1| |2|
> |1000403 |4| |1| |3|
> |1000403 |4| |4| |4|
> |10029943 |3| |1| |1|
> |10029943 |3| |1| |2|
> |10029943 |3| |3| |3|
> |10037980 |4| |1| |1|
> |10037980 |4| |1| |2|
> |10037980 |4| |1| |3|
> |10037980 |4| |4| |4|
> |10057418 |3| |1| |1|
> |10057418 |3| |1| |1|
> |10057418 |3| |1| |1|
> |1009550 |4| |1| |1|
> |1009550 |4| |1| |2|
> |1009550 |4| |1| |3|
> |1009550 |4| |4| |4|
>
>
> I get the correct value of I but in the wrong row but the vaule of J is correct in the first iteration and then it goes to 1
>
> Any help will be greatly appreciated
>         [[alternative HTML version deleted]]
>
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