### old way

```r
 df %>%
  mutate(row = row_number()) %>%
  gather('column', 'source', -row, -N)  # key = column, value = source, retain row and N
  # further transforms

```


### new way

```r
 df %>%
  mutate(row = row_number()) %>%
  pivot_longer(!c(row , N), names_to = 'column', values_to  = 'source') 
  # further transforms

```