PASSO 1 - cARREGAR BANCO DE DADOS

load("C:/Users/victo/Desktop/Base_de_dados-master/CARROS.RData")

PASSO 2 - TRANSFORMAR VARIÁVEIS

CARROS$Tipodecombustivel<-ifelse(CARROS$Tipodecombustivel==0, "Gas", "Alc")
CARROS$TipodeMarcha<-ifelse(CARROS$TipodeMarcha==0, "Auto", "Manual")

summary(CARROS)
##    Kmporlitro      Cilindros         Preco             HP       
##  Min.   :10.40   Min.   :4.000   Min.   : 71.1   Min.   : 52.0  
##  1st Qu.:15.43   1st Qu.:4.000   1st Qu.:120.8   1st Qu.: 96.5  
##  Median :19.20   Median :6.000   Median :196.3   Median :123.0  
##  Mean   :20.09   Mean   :6.188   Mean   :230.7   Mean   :146.7  
##  3rd Qu.:22.80   3rd Qu.:8.000   3rd Qu.:326.0   3rd Qu.:180.0  
##  Max.   :33.90   Max.   :8.000   Max.   :472.0   Max.   :335.0  
##  Amperagem_circ_eletrico      Peso            RPM        Tipodecombustivel 
##  Min.   :2.760           Min.   :1.513   Min.   :14.50   Length:32         
##  1st Qu.:3.080           1st Qu.:2.581   1st Qu.:16.89   Class :character  
##  Median :3.695           Median :3.325   Median :17.71   Mode  :character  
##  Mean   :3.597           Mean   :3.217   Mean   :17.85                     
##  3rd Qu.:3.920           3rd Qu.:3.610   3rd Qu.:18.90                     
##  Max.   :4.930           Max.   :5.424   Max.   :22.90                     
##  TipodeMarcha        NumdeMarchas   NumdeValvulas  
##  Length:32          Min.   :3.000   Min.   :1.000  
##  Class :character   1st Qu.:3.000   1st Qu.:2.000  
##  Mode  :character   Median :4.000   Median :2.000  
##                     Mean   :3.688   Mean   :2.812  
##                     3rd Qu.:4.000   3rd Qu.:4.000  
##                     Max.   :5.000   Max.   :8.000

#PASSO 3 - ANÁLISE EXPLORATÓRIA DE DADOS -AED #KM/L, HP, PREÇO DO CARRO - QUANTITATIVAS

boxplot(CARROS$Preco ~ CARROS$Tipodecombustivel,
        horizontal = T,
        col=c("red","blue"),
        main="O boxplot",
        xlab = "Preço do Carro",
        ylab = "Tipo de combustível")

graf2<-boxplot(CARROS$Kmporlitro ~ CARROS$Tipodecombustivel,
        horizontal = T,
        col=c("red","blue"),
        main="O boxplot 2",
        xlab = "Km/l do carro",
        ylab = "Tipo de combustível")

graf3<-boxplot(CARROS$HP ~ CARROS$TipodeMarcha,
        horizontal = T,
        col=c("green","yellow"),
        main="O boxplot 3",
        xlab = "HP",
        ylab = "Tipo de marcha")

par(mfrow=c(1,2))
graf2
## $stats
##      [,1]  [,2]
## [1,] 17.8 10.40
## [2,] 21.4 14.70
## [3,] 22.8 15.65
## [4,] 30.4 19.20
## [5,] 33.9 21.00
## 
## $n
## [1] 14 18
## 
## $conf
##          [,1]     [,2]
## [1,] 18.99955 13.97416
## [2,] 26.60045 17.32584
## 
## $out
## [1] 26
## 
## $group
## [1] 2
## 
## $names
## [1] "Alc" "Gas"
graf3
## $stats
##       [,1] [,2]
## [1,]  62.0   52
## [2,] 116.5   66
## [3,] 175.0  109
## [4,] 192.5  113
## [5,] 245.0  175
## 
## $n
## [1] 19 13
## 
## $conf
##          [,1]      [,2]
## [1,] 147.4518  88.40398
## [2,] 202.5482 129.59602
## 
## $out
## [1] 264 335
## 
## $group
## [1] 2 2
## 
## $names
## [1] "Auto"   "Manual"

#PASSO 4 - INSTALAR PACOTE PSYCH #PARA RESUMO DE DADOS

library(psych)

describeBy(Preco ~ Tipodecombustivel, data=CARROS)
## 
##  Descriptive statistics by group 
## Tipodecombustivel: Alc
##    vars  n   mean    sd median trimmed   mad  min max range skew kurtosis    se
## X1    1 14 132.46 56.89 120.55  127.11 61.82 71.1 258 186.9  0.8    -0.49 15.21
## ------------------------------------------------------------ 
## Tipodecombustivel: Gas
##    vars  n   mean     sd median trimmed   mad   min max range  skew kurtosis
## X1    1 18 307.15 106.77    311  308.52 72.65 120.3 472 351.7 -0.26    -1.06
##       se
## X1 25.16
describeBy(HP ~ TipodeMarcha, data=CARROS)
## 
##  Descriptive statistics by group 
## TipodeMarcha: Auto
##    vars  n   mean    sd median trimmed  mad min max range  skew kurtosis    se
## X1    1 19 160.26 53.91    175  161.06 77.1  62 245   183 -0.01    -1.21 12.37
## ------------------------------------------------------------ 
## TipodeMarcha: Manual
##    vars  n   mean    sd median trimmed   mad min max range skew kurtosis    se
## X1    1 13 126.85 84.06    109  114.73 63.75  52 335   283 1.36     0.56 23.31
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
CARROS %>%
  group_by(TipodeMarcha) %>%
  select(Tipodecombustivel) %>%
  table()
## Adding missing grouping variables: `TipodeMarcha`
##             Tipodecombustivel
## TipodeMarcha Alc Gas
##       Auto     7  12
##       Manual   7   6
CARROS %>%
  filter(Tipodecombustivel=="Gas") %>%
  group_by(TipodeMarcha) %>%
  select(HP) %>%
  summarise(media=mean(HP),n=n())
## Adding missing grouping variables: `TipodeMarcha`
## # A tibble: 2 x 3
##   TipodeMarcha media     n
## * <chr>        <dbl> <int>
## 1 Auto          194.    12
## 2 Manual        181.     6

#associacao linear relacao posistiva

plot(CARROS$HP,CARROS$Preco,pch=19)
abline(lsfit(CARROS$HP,CARROS$Preco),col="darkred")

cor(CARROS$HP,CARROS$Preco) #positiva forte, prox de 1
## [1] 0.7909486
#associacao linear relacao negativa
plot(CARROS$HP,CARROS$Kmporlitrom, pch=19)
abline(lsfit(CARROS$HP,CARROS$Kmporlitro),col="blue")

cor(CARROS$HP,CARROS$Kmporlitro) #negativa forte, prox de 1
## [1] -0.7761684

somente variáveis quantitativas

names(CARROS)
##  [1] "Kmporlitro"              "Cilindros"              
##  [3] "Preco"                   "HP"                     
##  [5] "Amperagem_circ_eletrico" "Peso"                   
##  [7] "RPM"                     "Tipodecombustivel"      
##  [9] "TipodeMarcha"            "NumdeMarchas"           
## [11] "NumdeValvulas"
variaveis_quanti<-c("Kmporlitro", "Preco", "HP", "Amperagem_circ_eletrico", "Peso", "RPM")

CARROS[,variaveis_quanti]
##                     Kmporlitro Preco  HP Amperagem_circ_eletrico  Peso   RPM
## Mazda RX4                 21.0 160.0 110                    3.90 2.620 16.46
## Mazda RX4 Wag             21.0 160.0 110                    3.90 2.875 17.02
## Datsun 710                22.8 108.0  93                    3.85 2.320 18.61
## Hornet 4 Drive            21.4 258.0 110                    3.08 3.215 19.44
## Hornet Sportabout         18.7 360.0 175                    3.15 3.440 17.02
## Valiant                   18.1 225.0 105                    2.76 3.460 20.22
## Duster 360                14.3 360.0 245                    3.21 3.570 15.84
## Merc 240D                 24.4 146.7  62                    3.69 3.190 20.00
## Merc 230                  22.8 140.8  95                    3.92 3.150 22.90
## Merc 280                  19.2 167.6 123                    3.92 3.440 18.30
## Merc 280C                 17.8 167.6 123                    3.92 3.440 18.90
## Merc 450SE                16.4 275.8 180                    3.07 4.070 17.40
## Merc 450SL                17.3 275.8 180                    3.07 3.730 17.60
## Merc 450SLC               15.2 275.8 180                    3.07 3.780 18.00
## Cadillac Fleetwood        10.4 472.0 205                    2.93 5.250 17.98
## Lincoln Continental       10.4 460.0 215                    3.00 5.424 17.82
## Chrysler Imperial         14.7 440.0 230                    3.23 5.345 17.42
## Fiat 128                  32.4  78.7  66                    4.08 2.200 19.47
## Honda Civic               30.4  75.7  52                    4.93 1.615 18.52
## Toyota Corolla            33.9  71.1  65                    4.22 1.835 19.90
## Toyota Corona             21.5 120.1  97                    3.70 2.465 20.01
## Dodge Challenger          15.5 318.0 150                    2.76 3.520 16.87
## AMC Javelin               15.2 304.0 150                    3.15 3.435 17.30
## Camaro Z28                13.3 350.0 245                    3.73 3.840 15.41
## Pontiac Firebird          19.2 400.0 175                    3.08 3.845 17.05
## Fiat X1-9                 27.3  79.0  66                    4.08 1.935 18.90
## Porsche 914-2             26.0 120.3  91                    4.43 2.140 16.70
## Lotus Europa              30.4  95.1 113                    3.77 1.513 16.90
## Ford Pantera L            15.8 351.0 264                    4.22 3.170 14.50
## Ferrari Dino              19.7 145.0 175                    3.62 2.770 15.50
## Maserati Bora             15.0 301.0 335                    3.54 3.570 14.60
## Volvo 142E                21.4 121.0 109                    4.11 2.780 18.60
cor(CARROS[,variaveis_quanti])
##                         Kmporlitro      Preco         HP
## Kmporlitro               1.0000000 -0.8475514 -0.7761684
## Preco                   -0.8475514  1.0000000  0.7909486
## HP                      -0.7761684  0.7909486  1.0000000
## Amperagem_circ_eletrico  0.6811719 -0.7102139 -0.4487591
## Peso                    -0.8676594  0.8879799  0.6587479
## RPM                      0.4186840 -0.4336979 -0.7082234
##                         Amperagem_circ_eletrico       Peso         RPM
## Kmporlitro                           0.68117191 -0.8676594  0.41868403
## Preco                               -0.71021393  0.8879799 -0.43369788
## HP                                  -0.44875912  0.6587479 -0.70822339
## Amperagem_circ_eletrico              1.00000000 -0.7124406  0.09120476
## Peso                                -0.71244065  1.0000000 -0.17471588
## RPM                                  0.09120476 -0.1747159  1.00000000
plot(CARROS$Amperagem_circ_eletrico, CARROS$RPM)
abline(lsfit(CARROS$Amperagem_circ_eletrico,CARROS$RPM),col="blue")

cor(CARROS$Amperagem_circ_eletrico,CARROS$RPM)
## [1] 0.09120476
#muito próxima de zero.

#visualizar matriz

library(corrplot)
## corrplot 0.84 loaded
correlacao_carros<-cor(CARROS[,variaveis_quanti])
correlacao_carros
##                         Kmporlitro      Preco         HP
## Kmporlitro               1.0000000 -0.8475514 -0.7761684
## Preco                   -0.8475514  1.0000000  0.7909486
## HP                      -0.7761684  0.7909486  1.0000000
## Amperagem_circ_eletrico  0.6811719 -0.7102139 -0.4487591
## Peso                    -0.8676594  0.8879799  0.6587479
## RPM                      0.4186840 -0.4336979 -0.7082234
##                         Amperagem_circ_eletrico       Peso         RPM
## Kmporlitro                           0.68117191 -0.8676594  0.41868403
## Preco                               -0.71021393  0.8879799 -0.43369788
## HP                                  -0.44875912  0.6587479 -0.70822339
## Amperagem_circ_eletrico              1.00000000 -0.7124406  0.09120476
## Peso                                -0.71244065  1.0000000 -0.17471588
## RPM                                  0.09120476 -0.1747159  1.00000000
corrplot(correlacao_carros)

corrplot.mixed(correlacao_carros)

Conclusão

Dois tipos de análise: