The dim() function is an inbuilt R function that either sets or returns the dimension of the matrix, array, or data frame. The dim() function takes the R object as an argument and returns its dimension, or if you assign the value to the dim() function, then it sets the dimension for that R Object.
The str() function in R Language is used for compactly displaying the internal structure of a R object. It can display even the internal structure of large lists which are nested. It provides one liner output for the basic R objects letting the user know about the object and its constituents.
Finally, the commonly used summary() function is applied to each column of the specified data frame. This function returns a data synopsis of the range of values each column posesses.
We’ll use the “palmerpenguins” package for this example.
library(palmerpenguins)
data(penguins)penguin_data <- data.frame(Flipper_Length = penguins$flipper_length_mm,
Bill_Length = penguins$bill_length_mm,
Bill_Depth = penguins$bill_depth_mm)dim(penguin_data) # retrieve columns and rows## [1] 344 3str(penguin_data) # summary of structure of data frame## 'data.frame': 344 obs. of 3 variables:
## $ Flipper_Length: int 181 186 195 NA 193 190 181 195 193 190 ...
## $ Bill_Length : num 39.1 39.5 40.3 NA 36.7 39.3 38.9 39.2 34.1 42 ...
## $ Bill_Depth : num 18.7 17.4 18 NA 19.3 20.6 17.8 19.6 18.1 20.2 ...summary(penguin_data) # synopsis of data parameters and ranges## Flipper_Length Bill_Length Bill_Depth
## Min. :172.0 Min. :32.10 Min. :13.10
## 1st Qu.:190.0 1st Qu.:39.23 1st Qu.:15.60
## Median :197.0 Median :44.45 Median :17.30
## Mean :200.9 Mean :43.92 Mean :17.15
## 3rd Qu.:213.0 3rd Qu.:48.50 3rd Qu.:18.70
## Max. :231.0 Max. :59.60 Max. :21.50
## NA's :2 NA's :2 NA's :2