How to count the number of groupings of elements in a data frame subject to multiple conditions usin-CodePudding

In the below example data frame myDF, I am trying to figure out the base R or dplyr code to derive the number of groupings of elements whereby Group code <> 0. For example in this data frame, with the generating code beneath and dput() version at the very bottom, I would like to get two different outputs:

a single digit output of 4 (where Elements R with Group = 1, X with Group = 1, R with Group 2, and X with Group -3, comprise the 4 groupings), and
an output show only those grouped elements (listing out those grouped elements listed in the above bullet).

Any recommendations for a simple and concise way to do this?

> myDF
   Element Group
1        R     1
2        R     1
3        X     0
4        X     1
5        X     1
6        X     0
7        B     0
8        R     0
9        R     2
10       R     2
11       X    -3
12       X    -3
13       X    -3

Generating code:

    myDF <- data.frame(
      Element = c("R","R","X","X","X","X","B","R","R","R","X","X","X"),
      Group = c(1,1,0,1,1,0,0,0,2,2,-3,-3,-3)
    )

Dput(myDF):

> dput(myDF)
structure(list(Element = c("R", "R", "X", "X", "X", "X", "B", 
"R", "R", "R", "X", "X", "X"), Group = c(1, 1, 0, 1, 1, 0, 0, 
0, 2, 2, -3, -3, -3)), class = "data.frame", row.names = c(NA, 
-13L))

CodePudding user response：

In dplyr:

filter(myDF, Group !=0) %>% distinct()

gives

  Element Group
1       R     1
2       X     1
3       R     2
4       X    -3