How to flatten data.frame for use with googlevis treemap? - r

Question

In order to use the treemap function on googleVis, data needs to be flattened into two columns. Using their example:
> library(googleVis)
> Regions
Region Parent Val Fac
1 Global <NA> 10 2
2 America Global 2 4
3 Europe Global 99 11
4 Asia Global 10 8
5 France Europe 71 2
6 Sweden Europe 89 3
7 Germany Europe 58 10
8 Mexico America 2 9
9 USA America 38 11
10 China Asia 5 1
11 Japan Asia 48 11
However, in the real world this information more frequently looks like this:
> a <- data.frame(
+ scal=c("Global", "Global", "Global", "Global", "Global", "Global", "Global"),
+ cont=c("Europe", "Europe", "Europe", "America", "America", "Asia", "Asia"),
+ country=c("France", "Sweden", "Germany", "Mexico", "USA", "China", "Japan"),
+ val=c(71, 89, 58, 2, 38, 5, 48),
+ fac=c(2,3,10,9,11,1,11))
> a
scal cont country val fac
1 Global Europe France 71 2
2 Global Europe Sweden 89 3
3 Global Europe Germany 58 10
4 Global America Mexico 2 9
5 Global America USA 38 11
6 Global Asia China 5 1
7 Global Asia Japan 48 11
But how to most efficiently change transform this data?

Answer 1

If we use dplyr, this script will transform the data correctly:
library(dplyr)
cbind(NA,a %>% group_by(scal) %>% summarize(val=sum(val),fac=sum(fac))) -> topLev
names(topLev) <- c("Parent","Region","val","fac")
a %>% group_by(scal,cont) %>% summarize(val=sum(val),fac=sum(fac)) %>%
select(Region=cont,Parent=scal,val,fac) -> midLev
a[,2:5] %>% select(Region=country,Parent=cont,val,fac) -> bottomLev
bind_rows(topLev,midLev,bottomLev) %>% select(2,1,3,4) -> answer
We can verify this by comparing dataframes:
> answer
Source: local data frame [11 x 4]
Region Parent val fac
1 Global NA 311 47
2 America Global 40 20
3 Asia Global 53 12
4 Europe Global 218 15
5 France Europe 71 2
6 Sweden Europe 89 3
7 Germany Europe 58 10
8 Mexico America 2 9
9 USA America 38 11
10 China Asia 5 1
11 Japan Asia 48 11
> Regions
Region Parent Val Fac
1 Global <NA> 10 2
2 America Global 2 4
3 Europe Global 99 11
4 Asia Global 10 8
5 France Europe 71 2
6 Sweden Europe 89 3
7 Germany Europe 58 10
8 Mexico America 2 9
9 USA America 38 11
10 China Asia 5 1
11 Japan Asia 48 11
Interesting that the summaries for the continents and the globe aren't the sum of their components (or min/max/ave/mean/normalized...)