Learn R: How to Create Data Frames Using Existing Data Frames

this article represents commands that could be used to create data frames using existing data frames . please feel free to comment/suggest if i failed to mention one or more important points. following is a list of command summaries for creating data frames by extracting multiple columns from existing data frame based on the following criteria, a sample of which is provided later in this article:

6 techniques for a extracting data frame from existing data frames

the following commands have been based on the diamonds data frame which is loaded as part of loading the ggplot2 library.

the following code shows how the diamonds data frame looks:

#1: create data frame with selected columns using column indices
# displays column carat, cut, depth
dfnew1 <- diamonds[,c(1,2,5)]

#2: create a data frame with the selected columns using column indices with sequences
# displays column carat, cut, color, depth, price, x
dfnew2 <- diamonds[, c(1:3, 5, 7:8)]

#3: create a data frame with selected columns using the data.frame command
# displays column carat, cut, color
dfnew3 <- data.frame(diamonds$carat, diamonds$cut, diamonds$color)
names(dfnew3) <- c("carat", "cut", "color")

#4: create a data frame using the selected columns and column names
# displays column carat, depth, price
dfnew4 <- diamonds[,c("carat", "depth", "price")]

#5: create a data frame using the subset command and column names
# displays column color, carat, price
dfnew5 <- subset(diamonds, select=c("color", "carat", "price"))

#6: create a data frame using the subset command and column indices
# displays column carat, cut, color, depth
dfnew6 <- subset(diamonds, select=c(1:3, 5))