R Data Frames
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
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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
summary(Data_Frame)
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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
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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
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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
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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
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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)
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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)
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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)
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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
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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
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