A data frame is more general than a matrix in that different collums can have different modes. Matrix is a collection of data elements. Data frame is used for storing data tables
Upload the ncbirths.csv file; save it in the data folder; and upload it into the data folder. Revise the read.csv code line so that the code matches both the name and address of the data file. The row represent newborns and the column characteristics of the newborns.
ncbirths <- read.csv("data/ncbirths.csv")
str(ncbirths)
## 'data.frame': 1000 obs. of 13 variables:
## $ fage : int NA NA 19 21 NA NA 18 17 NA 20 ...
## $ mage : int 13 14 15 15 15 15 15 15 16 16 ...
## $ mature : Factor w/ 2 levels "mature mom","younger mom": 2 2 2 2 2 2 2 2 2 2 ...
## $ weeks : int 39 42 37 41 39 38 37 35 38 37 ...
## $ premie : Factor w/ 3 levels "<NA>","full term",..: 2 2 2 2 2 2 2 3 2 2 ...
## $ visits : int 10 15 11 6 9 19 12 5 9 13 ...
## $ marital : Factor w/ 3 levels "<NA>","married",..: 2 2 2 2 2 2 2 2 2 2 ...
## $ gained : int 38 20 38 34 27 22 76 15 NA 52 ...
## $ weight : num 7.63 7.88 6.63 8 6.38 5.38 8.44 4.69 8.81 6.94 ...
## $ lowbirthweight: Factor w/ 2 levels "low","not low": 2 2 2 2 2 1 2 1 2 2 ...
## $ gender : Factor w/ 2 levels "female","male": 2 2 1 2 1 2 2 2 2 1 ...
## $ habit : Factor w/ 3 levels "<NA>","nonsmoker",..: 2 2 2 2 2 2 2 2 2 2 ...
## $ whitemom : Factor w/ 3 levels "<NA>","not white",..: 2 2 3 3 2 2 2 2 3 3 ...
summary(ncbirths)
## fage mage mature weeks
## Min. :14.00 Min. :13 mature mom :133 Min. :20.00
## 1st Qu.:25.00 1st Qu.:22 younger mom:867 1st Qu.:37.00
## Median :30.00 Median :27 Median :39.00
## Mean :30.26 Mean :27 Mean :38.33
## 3rd Qu.:35.00 3rd Qu.:32 3rd Qu.:40.00
## Max. :55.00 Max. :50 Max. :45.00
## NA's :171 NA's :2
## premie visits marital gained
## <NA> : 2 Min. : 0.0 <NA> : 1 Min. : 0.00
## full term:846 1st Qu.:10.0 married :386 1st Qu.:20.00
## premie :152 Median :12.0 not married:613 Median :30.00
## Mean :12.1 Mean :30.33
## 3rd Qu.:15.0 3rd Qu.:38.00
## Max. :30.0 Max. :85.00
## NA's :9 NA's :27
## weight lowbirthweight gender habit
## Min. : 1.000 low :111 female:503 <NA> : 1
## 1st Qu.: 6.380 not low:889 male :497 nonsmoker:873
## Median : 7.310 smoker :126
## Mean : 7.101
## 3rd Qu.: 8.060
## Max. :11.750
##
## whitemom
## <NA> : 2
## not white:284
## white :714
##
##
##
## Hint: See the number of observations under the structure of the data set. There are 1,000 newborns in the data set
Hint: See the number of variables under the structure of the data set. There are 13 columns under the structure of the data set