data frame

Data Frames

Data Frames are data displayed in a format as a table.

Data Frames can have different types of data inside it. While the first column can be character, the second and third can be numeric or logical. However, each column should have the same type of data.

Use the data.frame() function to create a data frame:

Example # Create a data frame

Data_Frame <- data.frame (
  Training = c("Strength", "Stamina", "Other"),
  Pulse = c(100, 150, 120),
  Duration = c(60, 30, 45)
)
# Print the data frame
Data_Frame

##   Training Pulse Duration
## 1 Strength   100       60
## 2  Stamina   150       30
## 3    Other   120       45

Summarize the Data

Use the summary() function to summarize the data from a Data Frame:

Example

Data_Frame <- data.frame (
  Training = c("Strength", "Stamina", "Other"),
  Pulse = c(100, 150, 120),
  Duration = c(60, 30, 45)
)

Data_Frame

##   Training Pulse Duration
## 1 Strength   100       60
## 2  Stamina   150       30
## 3    Other   120       45

summary(Data_Frame)

##    Training             Pulse          Duration   
##  Length:3           Min.   :100.0   Min.   :30.0  
##  Class :character   1st Qu.:110.0   1st Qu.:37.5  
##  Mode  :character   Median :120.0   Median :45.0  
##                     Mean   :123.3   Mean   :45.0  
##                     3rd Qu.:135.0   3rd Qu.:52.5  
##                     Max.   :150.0   Max.   :60.0

You will learn more about the summary() function in the statistical part of the R tutorial.

Access Items We can use single brackets [ ], double brackets [[ ]] or $ to access columns from a data frame:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Data_Frame[1]

Data_Frame[[“Training”]]

Data_Frame$Training Add Rows Use the rbind() function to add new rows in a Data Frame:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Add a new row

New_row_DF <- rbind(Data_Frame, c(“Strength”, 110, 110))

Print the new row

New_row_DF Add Columns Use the cbind() function to add new columns in a Data Frame:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Add a new column

New_col_DF <- cbind(Data_Frame, Steps = c(1000, 6000, 2000))

Print the new column

New_col_DF Remove Rows and Columns Use the c() function to remove rows and columns in a Data Frame:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Remove the first row and column

Data_Frame_New <- Data_Frame[-c(1), -c(1)]

Print the new data frame

Data_Frame_New Amount of Rows and Columns Use the dim() function to find the amount of rows and columns in a Data Frame:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

dim(Data_Frame) You can also use the ncol() function to find the number of columns and nrow() to find the number of rows:

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

ncol(Data_Frame) nrow(Data_Frame) Data Frame Length Use the length() function to find the number of columns in a Data Frame (similar to ncol()):

Example Data_Frame <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

length(Data_Frame) Combining Data Frames Use the rbind() function to combine two or more data frames in R vertically:

Example Data_Frame1 <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Data_Frame2 <- data.frame ( Training = c(“Stamina”, “Stamina”, “Strength”), Pulse = c(140, 150, 160), Duration = c(30, 30, 20) )

New_Data_Frame <- rbind(Data_Frame1, Data_Frame2) New_Data_Frame And use the cbind() function to combine two or more data frames in R horizontally:

Example Data_Frame3 <- data.frame ( Training = c(“Strength”, “Stamina”, “Other”), Pulse = c(100, 150, 120), Duration = c(60, 30, 45) )

Data_Frame4 <- data.frame ( Steps = c(3000, 6000, 2000), Calories = c(300, 400, 300) )

New_Data_Frame1 <- cbind(Data_Frame3, Data_Frame4) New_Data_Frame1