How to extract rows corresponding to specific names in R language?

In the R language, you can extract rows corresponding to a certain name using the following method:

1. Utilize logical indexing: by using a logical vector to select the rows that meet certain conditions. Start by creating a logical vector where TRUE corresponds to the rows you want to select and FALSE corresponds to the rows you want to exclude. Then apply this logical vector to the row index of the dataframe to extract the desired rows.

# 创建一个示例数据框
data <- data.frame(
  name = c("A", "B", "C", "D"),
  value = c(1, 2, 3, 4)
)

# 创建一个逻辑向量，选择name为"C"和"D"的行
logical_vector <- data$name %in% c("C", "D")

# 使用逻辑索引提取满足条件的行
selected_rows <- data[logical_vector, ]

1. With the subset function, you can extract rows that meet specified conditions. You can use a data frame and a conditional expression as arguments for the subset function.

# 使用subset函数提取name为"C"和"D"的行
selected_rows <- subset(data, name %in% c("C", "D"))

No matter which method is used, the corresponding rows can be extracted based on the name of the conditions.