Example 5-71 Programming with select

This example uses the select_ function to select columns from the IRIS ore.frame object that is created by using the ore.push function on the iris data.frame object.

IRIS <- ore.push(iris)
# Use ~, double quote, or quote function to specify the column to select
head(select_(IRIS, ~Petal.Length))
head(select_(IRIS, "Petal.Length"))
head(select_(IRIS, quote(-Petal.Length), quote(-Petal.Width)))
head(select_(IRIS, .dots = list(quote(-Petal.Length), quote(-Petal.Width))))

Listing for This Example

R> IRIS <- ore.push(iris)
R> # Use ~, double quote, or quote function to specify the column to select
R> head(select_(IRIS, ~Petal.Length))
  Petal.Length
1          1.4
2          1.4
3          1.3
4          1.5
5          1.4
6          1.7
R> head(select_(IRIS, "Petal.Length"))
  Petal.Length
1          1.4
2          1.4
3          1.3
4          1.5
5          1.4
6          1.7
R> head(select_(IRIS, quote(-Petal.Length), quote(-Petal.Width)))
  Sepal.Length Sepal.Width Species
1          5.1         3.5  setosa
2          4.9         3.0  setosa
3          4.7         3.2  setosa
4          4.6         3.1  setosa
5          5.0         3.6  setosa
6          5.4         3.9  setosa
R> head(select_(IRIS, .dots = list(quote(-Petal.Length), quote(-Petal.Width))))
  Sepal.Length Sepal.Width Species
1          5.1         3.5  setosa
2          4.9         3.0  setosa
3          4.7         3.2  setosa
4          4.6         3.1  setosa
5          5.0         3.6  setosa
6          5.4         3.9  setosa