# [R] Beginner problem - using mod function to print odd numbers

David Carlson dc@r|@on @end|ng |rom t@mu@edu
Sun Jun 6 22:09:25 CEST 2021

```If the loop is necessary:

num <- vector()
for (i in 1:100) {
if(i %% 2 != 0) num <- c(num, i)
}
num

Or modify your code to this to get each odd number printed on a separate row:

for (i in 1:100) {
if(i %% 2 != 0) print(i)
}

David L Carlson

On Sun, Jun 6, 2021 at 3:21 PM David Carlson <dcarlson using tamu.edu> wrote:
>
> There is really no need for a loop:
>
> num <- 1:100
> num[ifelse(num %% 2 == 1, TRUE, FALSE)]
>
>  [1]  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
> [26] 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99
>
> David L Carlson
>
>
> On Sat, Jun 5, 2021 at 2:05 PM William Michels via R-help
> <r-help using r-project.org> wrote:
> >
> > > i <- 1L; span <- 1:100; result <- NA;
> > > for (i in span){
> > + ifelse(i %% 2 != 0, result[i] <- TRUE, result[i] <- FALSE)
> > + }
> > > span[result]
> >  [1]  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43
> > 45 47 49 51 53 55 57
> > [30] 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99
> > >
> >
> > HTH, Bill.
> >
> > W. Michels, Ph.D.
> >
> >
> > On Sat, Jun 5, 2021 at 12:55 AM Stefan Evert <stefanML using collocations.de> wrote:
> > >
> > > >
> > > > I don't understand. --
> > > >
> > > > 7%%2=1
> > > > 9%%2=1
> > > > 11%%2=1
> > > >
> > > > What aren't these numbers printing ?
> > > >
> > > > num<-0
> > > > for (i in 1:100){
> > > >  num<-num+i
> > > > if (num%%2 != 0)
> > > >  print(num)
> > > > }
> > >
> > > Your code tests the numbers
> > >
> > >         1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, …
> > >
> > > and correctly prints the odd ones among them.
> > >
> > > But I suppose that's not what you wanted to do?
> > >
> > > ______________________________________________
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