You can select portions of a data set, as shown in Example 3-3. The example pushes the iris data set to the database and gets the ore.frame object iris_of. It filters the data to produce iris_of_filtered, which contains the values from the rows of iris_of that have a petal length of less than 1.5 and that are in the Sepal.Length and Species columns. The example also filters the data using conditions, so that iris_of_filtered contains the values from iris_of that are of the setosa or versicolor species and that have a petal width of less than 2.0.
Example 3-3 Selecting Data by Value
iris_of <- ore.push(iris)
# Select sepal length and species where petal length is less than 1.5.
iris_of_filtered <- iris_of[iris_of$Petal.Length < 1.5,
c("Sepal.Length", "Species")]
names(iris_of_filtered)
nrow(iris_of_filtered)
head(iris_of_filtered, 3)
# Alternate syntax filtering.
iris_of_filtered <- subset(iris_of, Petal.Length < 1.5)
nrow(iris_of_filtered)
head(iris_of_filtered, 3)
# Using the AND and OR conditions in filtering.
# Select all rows with in which the species is setosa or versicolor.
# and the petal width is less than 2.0.
iris_of_filtered <- iris_of[(iris_of$Species == "setosa" |
iris_of$Species == "versicolor") &
iris_of$Petal.Width < 2.0,]
nrow(iris_of_filtered)
head(iris_of, 3)
Listing for Example 3-3
R> iris_of <- ore.push(iris)
R> # Select sepal length and species where petal length is less than 1.5.
R> iris_of_filtered <- iris_of[iris_of$Petal.Length < 1.5,
+ c("Sepal.Length", "Species")]
R> names(iris_of_filtered)
[1] "Sepal.Length" "Species"
R> nrow(iris_of_filtered)
[1] 24
R> head(iris_of_filtered, 3)
Sepal.Length Species
1 5.1 setosa
2 4.9 setosa
3 4.7 setosa
R> # Alternate syntax filtering.
R> iris_of_filtered <- subset(iris_of, Petal.Length < 1.5)
R> nrow(iris_of_filtered)[1] 24
R> head(iris_of_filtered, 3)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1 5.1 3.5 1.4 0.2 setosa
2 4.9 3.0 1.4 0.2 setosa
3 4.7 3.2 1.3 0.2 setosa
R> # Using the AND and OR conditions in filtering.
R> # Select all rows with in which the species is setosa or versicolor.
R> # and the petal width is less than 2.0.
R> iris_of_filtered <- iris_of[(iris_of$Species == "setosa" |
+ iris_of$Species == "versicolor") &
+ iris_of$Petal.Width < 2.0,]
R> nrow(iris_of_filtered)[1] 100
R> head(iris_of, 3)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1 5.1 3.5 1.4 0.2 setosa
2 4.9 3.0 1.4 0.2 setosa
3 4.7 3.2 1.3 0.2 setosa