data(mtcars)
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
mean(mtcars$mpg)
## [1] 20.09062
sd(mtcars$mpg)
## [1] 6.026948
ls()
## [1] "mtcars"
rm(x)
## Warning in rm(x): object 'x' not found
rm(list=ls())
classex=c(0,3,5,9,8,7,0,9,5,2,4,10,14,7,15,4,7,17,6,13)
sort(classex)[length(classex)/2]
## [1] 7
gender=c(0,1,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0)
classd=NULL
classd$classex=classex
classd$gender=gender
classd=as.data.frame(classd)
classd
## classex gender
## 1 0 0
## 2 3 1
## 3 5 0
## 4 9 1
## 5 8 0
## 6 7 0
## 7 0 0
## 8 9 1
## 9 5 0
## 10 2 0
## 11 4 0
## 12 10 0
## 13 14 0
## 14 7 0
## 15 15 0
## 16 4 0
## 17 7 0
## 18 17 0
## 19 6 1
## 20 13 0
attach(classd)
## The following objects are masked _by_ .GlobalEnv:
##
## classex, gender
classd[gender==1,]
## classex gender
## 2 3 1
## 4 9 1
## 8 9 1
## 19 6 1
summary(classd[gender==1,])
## classex gender
## Min. :3.00 Min. :1
## 1st Qu.:5.25 1st Qu.:1
## Median :7.50 Median :1
## Mean :6.75 Mean :1
## 3rd Qu.:9.00 3rd Qu.:1
## Max. :9.00 Max. :1
summary(classd[gender==0,])
## classex gender
## Min. : 0.000 Min. :0
## 1st Qu.: 4.000 1st Qu.:0
## Median : 7.000 Median :0
## Mean : 7.375 Mean :0
## 3rd Qu.:10.750 3rd Qu.:0
## Max. :17.000 Max. :0
length(gender)
## [1] 20
length(classex)
## [1] 20
mean(classex)
## [1] 7.25
range(classex)
## [1] 0 17
median(classex)
## [1] 7
table(classex)
## classex
## 0 2 3 4 5 6 7 8 9 10 13 14 15 17
## 2 1 1 2 2 1 3 1 2 1 1 1 1 1
#mode(classex)=7
Mode <- function(x) {
ux <- unique(x)
ux[which.max(tabulate(match(x, ux)))]
}
Mode(classex)
## [1] 7
plot(density(classex))
hist(classex)
summary(classex)
## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 0.00 4.00 7.00 7.25 9.25 17.00
quantile(classex,c(0,.1,.2,.3,.4,.5,.6,.7,.8,.9,1))
## 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
## 0.0 1.8 3.8 4.7 5.6 7.0 7.4 9.0 10.6 14.1 17.0
quantile(classex,c(0,.25,.5,.75,1))
## 0% 25% 50% 75% 100%
## 0.00 4.00 7.00 9.25 17.00
#install.packages("moments")
library(moments)
kurtosis(classex)
## [1] 2.443901
kurtosis(classex)
## [1] 2.443901
getwd()
## [1] "C:/Users/Dell/Documents"
setwd("C:/Users/Dell/Desktop")
dir()
## [1] "~$thonajay.docx"
## [2] "µTorrent.lnk"
## [3] "association.html"
## [4] "association.R"
## [5] "BigDiamonds.csv"
## [6] "boston schema.xlsx"
## [7] "boston.csv"
## [8] "Class-3-Public-Primary-Certification-Authority.pem.txt"
## [9] "dap class 4.R"
## [10] "dap_class_4.html"
## [11] "Data Analysis (1)"
## [12] "DataWrangling.pdf"
## [13] "desktop.ini"
## [14] "Diamond (7).csv"
## [15] "Diamond (8).csv"
## [16] "dump"
## [17] "dvd.csv"
## [18] "GoToWebinar.lnk"
## [19] "kushal.jpg"
## [20] "NTO01022363_07_May_2017_09_52_28_AM.pdf"
## [21] "Pythonajay.docx"
## [22] "remedial class ims.R"
## [23] "remedial_class_ims.html"
## [24] "rsconnect"
## [25] "stats class 2.R"
## [26] "stats_class_2.html"
## [27] "sts_gold_tweet.csv"
## [28] "SUINV.png"
## [29] "titanic2.csv"
## [30] "Wipro_Third_Party_DB_New_Format.xlsx"
## [31] "womensmarchtweets.csv"
dir(pattern = "csv")
## [1] "BigDiamonds.csv" "boston.csv" "Diamond (7).csv"
## [4] "Diamond (8).csv" "dvd.csv" "sts_gold_tweet.csv"
## [7] "titanic2.csv" "womensmarchtweets.csv"
#install.packages("sqldf")
library(sqldf)
## Loading required package: gsubfn
## Loading required package: proto
## Loading required package: RSQLite
data(mtcars)
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
sqldf("select avg(mpg),gear from mtcars group by gear ")
## Loading required package: tcltk
## Warning: Quoted identifiers should have class SQL, use DBI::SQL() if the
## caller performs the quoting.
## avg(mpg) gear
## 1 16.10667 3
## 2 24.53333 4
## 3 21.38000 5
sqldf("select *
from mtcars
where mpg > (
select avg(mpg)
from mtcars
)"
)
## mpg cyl disp hp drat wt qsec vs am gear carb
## 1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## 2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## 3 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## 4 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
## 5 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## 6 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## 7 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
## 8 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
## 9 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
## 10 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
## 11 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
## 12 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
## 13 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2
## 14 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2
#sqldf("select * from mtcars where mpg>avg(mpg)")