R Language 07- View data

Summarizes the common method to view the data:

function	Features
tail()	View the trailer
head()	View header
dim()	View Data Dimensions
str()	Give each field name and type
levels()	View all given level field
table()	The tabulated variables, where each group was observed
summary()	See generally distributed data, gives the minimum value, quantile information
names()	View the data field name

• dim()

dim(mtcars)
[1] 32 11

• str()

str(mtcars)

'data.frame':    32 obs. of  11 variables:
$ mpg : num  21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
$ cyl : num  6 6 4 6 8 6 8 4 4 6 ...
$ disp: num  160 160 108 258 360 ...
$ hp  : num  110 110 93 110 175 105 245 62 95 123 ...
$ drat: num  3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...

• summary()

summary(mtcars)

mpg             cyl       
Min.   :10.40   Min.   :4.000  
1st Qu.:15.43   1st Qu.:4.000  
Median :19.20   Median :6.000  
Mean   :20.09   Mean   :6.188  
3rd Qu.:22.80   3rd Qu.:8.000  
Max.   :33.90   Max.   :8.000

• names()

names(mtcars)
[1] "mpg"  "cyl"  "disp" "hp"   "drat" "wt"  
[7] "qsec" "vs"   "am"   "gear" "carb"

• table ()
  using the data table to view the data field newloanstatus

table(data$newLoanStatus)

normalloan problemloan                 #可以看到正常贷款和问题贷款计数
      94855       17015

• levels ()
  using the View level data levels of data creditlevel

levels(data$creditlevel)
[1] "AA" "A"  "B"  "C"  "D"  "E"  "HR"