如何使用 rbind 向 dataframe R 添加行

Question

I know this is a classic question and there are also similar ones in the archive, but I feel like the answers did not really apply to this case. Basically I want to take one dataframe (covid cases in Berlin per district), calculate the sum of the columns and create a new dataframe with a column representing the name of the district and another one representing the total number. So I wrote

covid_bln <- read.csv('https://www.berlin.de/lageso/gesundheit/infektionsepidemiologie-infektionsschutz/corona/tabelle-bezirke-gesamtuebersicht/index.php/index/all.csv?q=', sep=';')
c_tot<-data.frame('district'=c(), 'number'=c())
for (n in colnames(covid_bln[3:14])){
    x<-data.frame('district'=c(n), 'number'=c(sum(covid_bln$n)))
    c_tot<-rbind(c_tot, x)
    next
}
print(c_tot)

Which works properly with the names but returns only the number of cases for the 8th district, but for all the districts. If you have any suggestion, even involving the use of other functions, it would be great. Thank you

Answer 1

Here's a base R solution:

number <- colSums(covid_bln[3:14])
district <- names(covid_bln[3:14])
c_tot <- cbind.data.frame(district, number)
rownames(c_tot) <- NULL

# If you don't want rownames:
rownames(c_tot) <- NULL

This gives us:

                     district number
1                       mitte  16030
2    friedrichshain_kreuzberg  10679
3                      pankow  10849
4  charlottenburg_wilmersdorf  10664
5                     spandau   9450
6         steglitz_zehlendorf   9218
7       tempelhof_schoeneberg  12624
8                   neukoelln  14922
9           treptow_koepenick   6760
10        marzahn_hellersdorf   6960
11                lichtenberg   7601
12              reinickendorf   9752

Answer 2

I want to provide a solution using tidyverse . The final result is ordered alphabetically by districts

  c_tot <- covid_bln %>%
    select( mitte:reinickendorf) %>% 
    gather(district, number, mitte:reinickendorf) %>% 
    group_by(district) %>% 
    summarise(number = sum(number))

The rusult is

# A tibble: 12 x 2
   district                   number
 * <chr>                       <int>
 1 charlottenburg_wilmersdorf  10736
 2 friedrichshain_kreuzberg    10698
 3 lichtenberg                  7644
 4 marzahn_hellersdorf          7000
 5 mitte                       16064
 6 neukoelln                   14982
 7 pankow                      10885
 8 reinickendorf                9784
 9 spandau                      9486
10 steglitz_zehlendorf          9236
11 tempelhof_schoeneberg       12656
12 treptow_koepenick            6788