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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