Subset dataframe using a loop

Question

I have a data frame that looks like this:

index   ID   date              Amount
2       1001 2010-06-08         0
21      1001 2010-10-08        10
6       10         


        

Answer 1

Take a look at the list2env and split function. Hereby some examples using the iris dataset.

Two way:

list_df <- split(iris, iris$Species) #split the dataset into a list of datasets based on the value of iris$Species
list2env(list_DF, envir= .GlobalEnv) #split the list into separate datasets

One way:

list2env(split(iris, iris$Species), envir = .GlobalEnv)

Or you can assign custom names for the new datasets with a for loop:

iris_split <- split(iris, iris$Species)
new_names <- c("one", "two", "three")
for (i in 1:length(iris_split)) {
  assign(new_names[i], iris_split[[i]])
}

Updates with examples

Related post

Answer 2

    iris_split <- split(iris, iris$Species)

Dynamically you can assign the data.frame name

    new_names <- as.character(unique(iris$Species))

    for (i in 1:length(iris_split)) {
    assign(new_names[i], iris_split[[i]])
    }

Answer 3

may be like this

    IDs<-unique(df$ID)
    for (i in 1:length(IDs)){ 
    temp <- df[df$ID==IDs[i],]
    #more things to do with temp
    }