Dear R Users,

I have two data frame. Each of them has three columns but the number of rows is different. I would like to find the row indices of the longer data frame where its values exist in the other data frame. I tried the following:

```
ind = which(as.numeric(Results[,1])
%in% as.numeric(Hour.mean[,1])
& as.numeric(Results[,2]) %in% as.numeric(Hour.mean[,2])
& as.numeric(Results[,3]) %in% as.numeric(Hour.mean[,3])
)
```

but it does not give correct values. Could someone suggest me a solution?