Adding rows to data frame with zero values - r

Question

I have a dataset with multiple records, each of which is assigned a country, and I want to create a worldmap using rworldmap, coloured according to the frequency with which each country occurs in the dataset. Not all countries appear in the dataset - either because they have no corresponding records or because they are not eligible (e.g. middle/low income countries).
To build the map, I have created a dataframe (dfmap) based on a table of countries, where one column is the country code and the second column is the frequency with which it appears in the dataset.
In order to identify on the map countries which are eligible, but have no records, I have tried to use add_row to add these to my dataframe e.g. for Andorra:
add_row(dfmap, Var1="AND", Freq=0)
When I run add_row for each country, it appears to work (no error message and that new row appears in the table below the command) - but previously added rows where the Freq=0 do not appear.
When I then look at the dataframe using "dfmap" or "summary(dfmap)", none of the rows where Freq=0 appear, and when I build the map, they are coloured as for missing countries.
I'm not sure where I'm going wrong and would welcome any suggestions.
Many thanks

Answer 1

Using the method suggested in the comment above, one can use the join function and then the replace_na function to create a tibble with the complete country and give these a count value of zero.
As there was no sample data in the question i created two data frames below based on what I thought was implied by the question.
dfrm_counts = tibble(Country = c('England','Germany'),
Count = c(1,4))
dfrm_all = tibble(Country = c('England', 'Germany', 'France'))
dfrm_final = dfrm_counts %>%
right_join(dfrm_all, by = "Country") %>%
replace_na(list(Count = 0))
dfrm_final
# A tibble: 3 x 2
Country Count
<chr> <dbl>
1 England 1
2 Germany 4
3 France 0