Learn R – How to Create Data Frames using Existing Data Frame

This article represents commands that could be used to create data frames using existing data frame. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos.

• Column indices
• Column names
• Subset command
• Data.frame command

6 Techniques for Extracting Data Frame from Existing Data Frames

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

 

Following is how the diamonds data frame looks like:

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

#2: Create data frame with 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 data frame with selected columns using 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 data frame using selected columns and column names
# Displays column carat, depth, price
dfnew4 <- diamonds[,c("carat", "depth", "price")]

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

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