data(Cars93,package="MASS")
View(Cars93)
str(Cars93)
## 'data.frame':    93 obs. of  27 variables:
##  $ Manufacturer      : Factor w/ 32 levels "Acura","Audi",..: 1 1 2 2 3 4 4 4 4 5 ...
##  $ Model             : Factor w/ 93 levels "100","190E","240",..: 49 56 9 1 6 24 54 74 73 35 ...
##  $ Type              : Factor w/ 6 levels "Compact","Large",..: 4 3 1 3 3 3 2 2 3 2 ...
##  $ Min.Price         : num  12.9 29.2 25.9 30.8 23.7 14.2 19.9 22.6 26.3 33 ...
##  $ Price             : num  15.9 33.9 29.1 37.7 30 15.7 20.8 23.7 26.3 34.7 ...
##  $ Max.Price         : num  18.8 38.7 32.3 44.6 36.2 17.3 21.7 24.9 26.3 36.3 ...
##  $ MPG.city          : int  25 18 20 19 22 22 19 16 19 16 ...
##  $ MPG.highway       : int  31 25 26 26 30 31 28 25 27 25 ...
##  $ AirBags           : Factor w/ 3 levels "Driver & Passenger",..: 3 1 2 1 2 2 2 2 2 2 ...
##  $ DriveTrain        : Factor w/ 3 levels "4WD","Front",..: 2 2 2 2 3 2 2 3 2 2 ...
##  $ Cylinders         : Factor w/ 6 levels "3","4","5","6",..: 2 4 4 4 2 2 4 4 4 5 ...
##  $ EngineSize        : num  1.8 3.2 2.8 2.8 3.5 2.2 3.8 5.7 3.8 4.9 ...
##  $ Horsepower        : int  140 200 172 172 208 110 170 180 170 200 ...
##  $ RPM               : int  6300 5500 5500 5500 5700 5200 4800 4000 4800 4100 ...
##  $ Rev.per.mile      : int  2890 2335 2280 2535 2545 2565 1570 1320 1690 1510 ...
##  $ Man.trans.avail   : Factor w/ 2 levels "No","Yes": 2 2 2 2 2 1 1 1 1 1 ...
##  $ Fuel.tank.capacity: num  13.2 18 16.9 21.1 21.1 16.4 18 23 18.8 18 ...
##  $ Passengers        : int  5 5 5 6 4 6 6 6 5 6 ...
##  $ Length            : int  177 195 180 193 186 189 200 216 198 206 ...
##  $ Wheelbase         : int  102 115 102 106 109 105 111 116 108 114 ...
##  $ Width             : int  68 71 67 70 69 69 74 78 73 73 ...
##  $ Turn.circle       : int  37 38 37 37 39 41 42 45 41 43 ...
##  $ Rear.seat.room    : num  26.5 30 28 31 27 28 30.5 30.5 26.5 35 ...
##  $ Luggage.room      : int  11 15 14 17 13 16 17 21 14 18 ...
##  $ Weight            : int  2705 3560 3375 3405 3640 2880 3470 4105 3495 3620 ...
##  $ Origin            : Factor w/ 2 levels "USA","non-USA": 2 2 2 2 2 1 1 1 1 1 ...
##  $ Make              : Factor w/ 93 levels "Acura Integra",..: 1 2 4 3 5 6 7 9 8 10 ...
x<-data.frame(Cars93$Horsepower,Cars93$Wheelbase) #creates  Data frame
cor(x)
##                   Cars93.Horsepower Cars93.Wheelbase
## Cars93.Horsepower         1.0000000        0.4868542
## Cars93.Wheelbase          0.4868542        1.0000000
plot(x)

Regression Analysis on Cars93 dataset

names(Cars93)
##  [1] "Manufacturer"       "Model"              "Type"              
##  [4] "Min.Price"          "Price"              "Max.Price"         
##  [7] "MPG.city"           "MPG.highway"        "AirBags"           
## [10] "DriveTrain"         "Cylinders"          "EngineSize"        
## [13] "Horsepower"         "RPM"                "Rev.per.mile"      
## [16] "Man.trans.avail"    "Fuel.tank.capacity" "Passengers"        
## [19] "Length"             "Wheelbase"          "Width"             
## [22] "Turn.circle"        "Rear.seat.room"     "Luggage.room"      
## [25] "Weight"             "Origin"             "Make"
fit<-lm(Price~.,data=Cars93)
fit
## 
## Call:
## lm(formula = Price ~ ., data = Cars93)
## 
## Coefficients:
##                  (Intercept)              ManufacturerAudi  
##                         33.9                           3.8  
##              ManufacturerBMW             ManufacturerBuick  
##                         -3.9                         -10.2  
##         ManufacturerCadillac         ManufacturerChevrolet  
##                          6.2                         -18.0  
##         ManufacturerChrylser          ManufacturerChrysler  
##                        -15.5                         -18.1  
##            ManufacturerDodge             ManufacturerEagle  
##                         -8.1                         -14.6  
##             ManufacturerFord               ManufacturerGeo  
##                        -22.6                         -21.4  
##            ManufacturerHonda           ManufacturerHyundai  
##                        -14.1                         -20.0  
##         ManufacturerInfiniti             ManufacturerLexus  
##                         14.0                           1.3  
##          ManufacturerLincoln             ManufacturerMazda  
##                          2.2                         -22.3  
##    ManufacturerMercedes-Benz           ManufacturerMercury  
##                         28.0                         -19.0  
##       ManufacturerMitsubishi            ManufacturerNissan  
##                        -23.6                         -22.1  
##       ManufacturerOldsmobile          ManufacturerPlymouth  
##                        -13.2                         -19.5  
##          ManufacturerPontiac              ManufacturerSaab  
##                        -22.8                          -5.2  
##           ManufacturerSaturn            ManufacturerSubaru  
##                        -22.8                         -23.0  
##           ManufacturerSuzuki            ManufacturerToyota  
##                        -25.3                         -24.1  
##       ManufacturerVolkswagen             ManufacturerVolvo  
##                        -13.9                          -7.2  
##                    Model190E                      Model240  
##                        -30.0                          -4.0  
##                    Model300E                      Model323  
##                           NA                          -3.3  
##                    Model535i                      Model626  
##                           NA                           4.9  
##                     Model850                       Model90  
##                           NA                          -8.6  
##                     Model900                   ModelAccord  
##                           NA                          -2.3  
##                 ModelAchieva                   ModelAltima  
##                         -7.2                           3.9  
##              ModelBonneville                   ModelCamaro  
##                         13.3                          -0.8  
##                   ModelCamry                    ModelCapri  
##                          8.4                          -0.8  
##                 ModelCaprice                 ModelCavalier  
##                          2.9                          -2.5  
##                  ModelCelica                  ModelCentury  
##                          8.6                          -8.0  
##                   ModelCivic                     ModelColt  
##                         -7.7                         -16.6  
##                ModelConcorde              ModelContinental  
##                           NA                          -1.8  
##                 ModelCorrado                  ModelCorsica  
##                          3.3                          -4.5  
##                  ModelCougar           ModelCrown_Victoria  
##                           NA                           9.6  
##           ModelCutlass_Ciera                  ModelDeVille  
##                         -4.4                          -5.4  
##                ModelDiamante                  ModelDynasty  
##                         15.8                         -10.2  
##                   ModelES300             ModelEighty-Eight  
##                         -7.2                            NA  
##                 ModelElantra                   ModelEscort  
##                         -3.9                          -1.2  
##                   ModelExcel                  ModelFestiva  
##                         -5.9                          -3.9  
##                ModelFirebird                      ModelFox  
##                          6.6                         -10.9  
##              ModelGrand_Prix                 ModelImperial  
##                          7.4                          13.7  
##                 ModelIntegra                    ModelJusty  
##                        -18.0                          -2.5  
##                   ModelLaser                  ModelLeBaron  
##                           NA                            NA  
##                  ModelLeMans                  ModelLeSabre  
##                         -2.1                          -2.9  
##                  ModelLegacy                   ModelLegend  
##                          8.6                            NA  
##                  ModelLoyale                   ModelLumina  
##                           NA                            NA  
##                  ModelMaxima                    ModelMetro  
##                          9.7                          -4.1  
##                  ModelMirage                  ModelMustang  
##                           NA                           4.6  
##                  ModelPassat                  ModelPrelude  
##                           NA                            NA  
##                   ModelProbe                  ModelProtege  
##                          2.7                            NA  
##                     ModelQ45                  ModelRiviera  
##                           NA                           2.6  
##              ModelRoadmaster                    ModelSC300  
##                           NA                            NA  
##                      ModelSL                   ModelScoupe  
##                           NA                          -3.9  
##                  ModelSentra                  ModelSeville  
##                           NA                            NA  
##                  ModelShadow                   ModelSonata  
##                        -14.5                            NA  
##                  ModelSpirit                  ModelStealth  
##                        -12.5                            NA  
##                   ModelStorm                   ModelSummit  
##                           NA                          -7.1  
##                 ModelSunbird                    ModelSwift  
##                           NA                            NA  
##                  ModelTaurus                    ModelTempo  
##                          8.9                            NA  
##                  ModelTercel                 ModelTown_Car  
##                           NA                            NA  
##                  ModelVision                     TypeLarge  
##                           NA                            NA  
##                  TypeMidsize                     TypeSmall  
##                           NA                            NA  
##                   TypeSporty                     Min.Price  
##                           NA                            NA  
##                    Max.Price                      MPG.city  
##                           NA                            NA  
##                  MPG.highway            AirBagsDriver only  
##                           NA                            NA  
##                  AirBagsNone               DriveTrainFront  
##                           NA                            NA  
##               DriveTrainRear                    Cylinders4  
##                           NA                            NA  
##                   Cylinders5                    Cylinders6  
##                           NA                            NA  
##                   Cylinders8                    EngineSize  
##                           NA                            NA  
##                   Horsepower                           RPM  
##                           NA                            NA  
##                 Rev.per.mile            Man.trans.availYes  
##                           NA                            NA  
##           Fuel.tank.capacity                    Passengers  
##                           NA                            NA  
##                       Length                     Wheelbase  
##                           NA                            NA  
##                        Width                   Turn.circle  
##                           NA                            NA  
##               Rear.seat.room                  Luggage.room  
##                           NA                            NA  
##                       Weight                 Originnon-USA  
##                           NA                            NA  
##             MakeAcura Legend                  MakeAudi 100  
##                           NA                            NA  
##                  MakeAudi 90                  MakeBMW 535i  
##                           NA                            NA  
##            MakeBuick Century             MakeBuick LeSabre  
##                           NA                            NA  
##            MakeBuick Riviera          MakeBuick Roadmaster  
##                           NA                            NA  
##         MakeCadillac DeVille          MakeCadillac Seville  
##                           NA                            NA  
##         MakeChevrolet Camaro         MakeChevrolet Caprice  
##                           NA                            NA  
##       MakeChevrolet Cavalier         MakeChevrolet Corsica  
##                           NA                            NA  
##         MakeChevrolet Lumina         MakeChrylser Concorde  
##                           NA                            NA  
##        MakeChrysler Imperial          MakeChrysler LeBaron  
##                           NA                            NA  
##               MakeDodge Colt             MakeDodge Dynasty  
##                           NA                            NA  
##             MakeDodge Shadow              MakeDodge Spirit  
##                           NA                            NA  
##            MakeDodge Stealth              MakeEagle Summit  
##                           NA                            NA  
##             MakeEagle Vision       MakeFord Crown_Victoria  
##                           NA                            NA  
##              MakeFord Escort              MakeFord Festiva  
##                           NA                            NA  
##             MakeFord Mustang                MakeFord Probe  
##                           NA                            NA  
##              MakeFord Taurus                MakeFord Tempo  
##                           NA                            NA  
##                MakeGeo Metro                 MakeGeo Storm  
##                           NA                            NA  
##             MakeHonda Accord               MakeHonda Civic  
##                           NA                            NA  
##            MakeHonda Prelude           MakeHyundai Elantra  
##                           NA                            NA  
##            MakeHyundai Excel            MakeHyundai Scoupe  
##                           NA                            NA  
##           MakeHyundai Sonata              MakeInfiniti Q45  
##                           NA                            NA  
##              MakeLexus ES300               MakeLexus SC300  
##                           NA                            NA  
##      MakeLincoln Continental          MakeLincoln Town_Car  
##                           NA                            NA  
##                MakeMazda 323                 MakeMazda 626  
##                           NA                            NA  
##            MakeMazda Protege        MakeMercedes-Benz 190E  
##                           NA                            NA  
##       MakeMercedes-Benz 300E             MakeMercury Capri  
##                           NA                            NA  
##           MakeMercury Cougar       MakeMitsubishi Diamante  
##                           NA                            NA  
##        MakeMitsubishi Mirage             MakeNissan Altima  
##                           NA                            NA  
##            MakeNissan Maxima             MakeNissan Sentra  
##                           NA                            NA  
##       MakeOldsmobile Achieva  MakeOldsmobile Cutlass_Ciera  
##                           NA                            NA  
##  MakeOldsmobile Eighty-Eight            MakePlymouth Laser  
##                           NA                            NA  
##       MakePontiac Bonneville          MakePontiac Firebird  
##                           NA                            NA  
##       MakePontiac Grand_Prix            MakePontiac LeMans  
##                           NA                            NA  
##          MakePontiac Sunbird                  MakeSaab 900  
##                           NA                            NA  
##                MakeSaturn SL              MakeSubaru Justy  
##                           NA                            NA  
##            MakeSubaru Legacy             MakeSubaru Loyale  
##                           NA                            NA  
##             MakeSuzuki Swift              MakeToyota Camry  
##                           NA                            NA  
##            MakeToyota Celica             MakeToyota Tercel  
##                           NA                            NA  
##       MakeVolkswagen Corrado            MakeVolkswagen Fox  
##                           NA                            NA  
##        MakeVolkswagen Passat                 MakeVolvo 240  
##                           NA                            NA  
##                MakeVolvo 850  
##                           NA
summary(fit)
## 
## Call:
## lm(formula = Price ~ ., data = Cars93)
## 
## Residuals:
## ALL 82 residuals are 0: no residual degrees of freedom!
## 
## Coefficients: (143 not defined because of singularities)
##                              Estimate Std. Error t value Pr(>|t|)
## (Intercept)                      33.9         NA      NA       NA
## ManufacturerAudi                  3.8         NA      NA       NA
## ManufacturerBMW                  -3.9         NA      NA       NA
## ManufacturerBuick               -10.2         NA      NA       NA
## ManufacturerCadillac              6.2         NA      NA       NA
## ManufacturerChevrolet           -18.0         NA      NA       NA
## ManufacturerChrylser            -15.5         NA      NA       NA
## ManufacturerChrysler            -18.1         NA      NA       NA
## ManufacturerDodge                -8.1         NA      NA       NA
## ManufacturerEagle               -14.6         NA      NA       NA
## ManufacturerFord                -22.6         NA      NA       NA
## ManufacturerGeo                 -21.4         NA      NA       NA
## ManufacturerHonda               -14.1         NA      NA       NA
## ManufacturerHyundai             -20.0         NA      NA       NA
## ManufacturerInfiniti             14.0         NA      NA       NA
## ManufacturerLexus                 1.3         NA      NA       NA
## ManufacturerLincoln               2.2         NA      NA       NA
## ManufacturerMazda               -22.3         NA      NA       NA
## ManufacturerMercedes-Benz        28.0         NA      NA       NA
## ManufacturerMercury             -19.0         NA      NA       NA
## ManufacturerMitsubishi          -23.6         NA      NA       NA
## ManufacturerNissan              -22.1         NA      NA       NA
## ManufacturerOldsmobile          -13.2         NA      NA       NA
## ManufacturerPlymouth            -19.5         NA      NA       NA
## ManufacturerPontiac             -22.8         NA      NA       NA
## ManufacturerSaab                 -5.2         NA      NA       NA
## ManufacturerSaturn              -22.8         NA      NA       NA
## ManufacturerSubaru              -23.0         NA      NA       NA
## ManufacturerSuzuki              -25.3         NA      NA       NA
## ManufacturerToyota              -24.1         NA      NA       NA
## ManufacturerVolkswagen          -13.9         NA      NA       NA
## ManufacturerVolvo                -7.2         NA      NA       NA
## Model190E                       -30.0         NA      NA       NA
## Model240                         -4.0         NA      NA       NA
## Model300E                          NA         NA      NA       NA
## Model323                         -3.3         NA      NA       NA
## Model535i                          NA         NA      NA       NA
## Model626                          4.9         NA      NA       NA
## Model850                           NA         NA      NA       NA
## Model90                          -8.6         NA      NA       NA
## Model900                           NA         NA      NA       NA
## ModelAccord                      -2.3         NA      NA       NA
## ModelAchieva                     -7.2         NA      NA       NA
## ModelAltima                       3.9         NA      NA       NA
## ModelBonneville                  13.3         NA      NA       NA
## ModelCamaro                      -0.8         NA      NA       NA
## ModelCamry                        8.4         NA      NA       NA
## ModelCapri                       -0.8         NA      NA       NA
## ModelCaprice                      2.9         NA      NA       NA
## ModelCavalier                    -2.5         NA      NA       NA
## ModelCelica                       8.6         NA      NA       NA
## ModelCentury                     -8.0         NA      NA       NA
## ModelCivic                       -7.7         NA      NA       NA
## ModelColt                       -16.6         NA      NA       NA
## ModelConcorde                      NA         NA      NA       NA
## ModelContinental                 -1.8         NA      NA       NA
## ModelCorrado                      3.3         NA      NA       NA
## ModelCorsica                     -4.5         NA      NA       NA
## ModelCougar                        NA         NA      NA       NA
## ModelCrown_Victoria               9.6         NA      NA       NA
## ModelCutlass_Ciera               -4.4         NA      NA       NA
## ModelDeVille                     -5.4         NA      NA       NA
## ModelDiamante                    15.8         NA      NA       NA
## ModelDynasty                    -10.2         NA      NA       NA
## ModelES300                       -7.2         NA      NA       NA
## ModelEighty-Eight                  NA         NA      NA       NA
## ModelElantra                     -3.9         NA      NA       NA
## ModelEscort                      -1.2         NA      NA       NA
## ModelExcel                       -5.9         NA      NA       NA
## ModelFestiva                     -3.9         NA      NA       NA
## ModelFirebird                     6.6         NA      NA       NA
## ModelFox                        -10.9         NA      NA       NA
## ModelGrand_Prix                   7.4         NA      NA       NA
## ModelImperial                    13.7         NA      NA       NA
## ModelIntegra                    -18.0         NA      NA       NA
## ModelJusty                       -2.5         NA      NA       NA
## ModelLaser                         NA         NA      NA       NA
## ModelLeBaron                       NA         NA      NA       NA
## ModelLeMans                      -2.1         NA      NA       NA
## ModelLeSabre                     -2.9         NA      NA       NA
## ModelLegacy                       8.6         NA      NA       NA
## ModelLegend                        NA         NA      NA       NA
## ModelLoyale                        NA         NA      NA       NA
## ModelLumina                        NA         NA      NA       NA
## ModelMaxima                       9.7         NA      NA       NA
## ModelMetro                       -4.1         NA      NA       NA
## ModelMirage                        NA         NA      NA       NA
## ModelMustang                      4.6         NA      NA       NA
## ModelPassat                        NA         NA      NA       NA
## ModelPrelude                       NA         NA      NA       NA
## ModelProbe                        2.7         NA      NA       NA
## ModelProtege                       NA         NA      NA       NA
## ModelQ45                           NA         NA      NA       NA
## ModelRiviera                      2.6         NA      NA       NA
## ModelRoadmaster                    NA         NA      NA       NA
## ModelSC300                         NA         NA      NA       NA
## ModelSL                            NA         NA      NA       NA
## ModelScoupe                      -3.9         NA      NA       NA
## ModelSentra                        NA         NA      NA       NA
## ModelSeville                       NA         NA      NA       NA
## ModelShadow                     -14.5         NA      NA       NA
## ModelSonata                        NA         NA      NA       NA
## ModelSpirit                     -12.5         NA      NA       NA
## ModelStealth                       NA         NA      NA       NA
## ModelStorm                         NA         NA      NA       NA
## ModelSummit                      -7.1         NA      NA       NA
## ModelSunbird                       NA         NA      NA       NA
## ModelSwift                         NA         NA      NA       NA
## ModelTaurus                       8.9         NA      NA       NA
## ModelTempo                         NA         NA      NA       NA
## ModelTercel                        NA         NA      NA       NA
## ModelTown_Car                      NA         NA      NA       NA
## ModelVision                        NA         NA      NA       NA
## TypeLarge                          NA         NA      NA       NA
## TypeMidsize                        NA         NA      NA       NA
## TypeSmall                          NA         NA      NA       NA
## TypeSporty                         NA         NA      NA       NA
## Min.Price                          NA         NA      NA       NA
## Max.Price                          NA         NA      NA       NA
## MPG.city                           NA         NA      NA       NA
## MPG.highway                        NA         NA      NA       NA
## AirBagsDriver only                 NA         NA      NA       NA
## AirBagsNone                        NA         NA      NA       NA
## DriveTrainFront                    NA         NA      NA       NA
## DriveTrainRear                     NA         NA      NA       NA
## Cylinders4                         NA         NA      NA       NA
## Cylinders5                         NA         NA      NA       NA
## Cylinders6                         NA         NA      NA       NA
## Cylinders8                         NA         NA      NA       NA
## EngineSize                         NA         NA      NA       NA
## Horsepower                         NA         NA      NA       NA
## RPM                                NA         NA      NA       NA
## Rev.per.mile                       NA         NA      NA       NA
## Man.trans.availYes                 NA         NA      NA       NA
## Fuel.tank.capacity                 NA         NA      NA       NA
## Passengers                         NA         NA      NA       NA
## Length                             NA         NA      NA       NA
## Wheelbase                          NA         NA      NA       NA
## Width                              NA         NA      NA       NA
## Turn.circle                        NA         NA      NA       NA
## Rear.seat.room                     NA         NA      NA       NA
## Luggage.room                       NA         NA      NA       NA
## Weight                             NA         NA      NA       NA
## Originnon-USA                      NA         NA      NA       NA
## MakeAcura Legend                   NA         NA      NA       NA
## MakeAudi 100                       NA         NA      NA       NA
## MakeAudi 90                        NA         NA      NA       NA
## MakeBMW 535i                       NA         NA      NA       NA
## MakeBuick Century                  NA         NA      NA       NA
## MakeBuick LeSabre                  NA         NA      NA       NA
## MakeBuick Riviera                  NA         NA      NA       NA
## MakeBuick Roadmaster               NA         NA      NA       NA
## MakeCadillac DeVille               NA         NA      NA       NA
## MakeCadillac Seville               NA         NA      NA       NA
## MakeChevrolet Camaro               NA         NA      NA       NA
## MakeChevrolet Caprice              NA         NA      NA       NA
## MakeChevrolet Cavalier             NA         NA      NA       NA
## MakeChevrolet Corsica              NA         NA      NA       NA
## MakeChevrolet Lumina               NA         NA      NA       NA
## MakeChrylser Concorde              NA         NA      NA       NA
## MakeChrysler Imperial              NA         NA      NA       NA
## MakeChrysler LeBaron               NA         NA      NA       NA
## MakeDodge Colt                     NA         NA      NA       NA
## MakeDodge Dynasty                  NA         NA      NA       NA
## MakeDodge Shadow                   NA         NA      NA       NA
## MakeDodge Spirit                   NA         NA      NA       NA
## MakeDodge Stealth                  NA         NA      NA       NA
## MakeEagle Summit                   NA         NA      NA       NA
## MakeEagle Vision                   NA         NA      NA       NA
## MakeFord Crown_Victoria            NA         NA      NA       NA
## MakeFord Escort                    NA         NA      NA       NA
## MakeFord Festiva                   NA         NA      NA       NA
## MakeFord Mustang                   NA         NA      NA       NA
## MakeFord Probe                     NA         NA      NA       NA
## MakeFord Taurus                    NA         NA      NA       NA
## MakeFord Tempo                     NA         NA      NA       NA
## MakeGeo Metro                      NA         NA      NA       NA
## MakeGeo Storm                      NA         NA      NA       NA
## MakeHonda Accord                   NA         NA      NA       NA
## MakeHonda Civic                    NA         NA      NA       NA
## MakeHonda Prelude                  NA         NA      NA       NA
## MakeHyundai Elantra                NA         NA      NA       NA
## MakeHyundai Excel                  NA         NA      NA       NA
## MakeHyundai Scoupe                 NA         NA      NA       NA
## MakeHyundai Sonata                 NA         NA      NA       NA
## MakeInfiniti Q45                   NA         NA      NA       NA
## MakeLexus ES300                    NA         NA      NA       NA
## MakeLexus SC300                    NA         NA      NA       NA
## MakeLincoln Continental            NA         NA      NA       NA
## MakeLincoln Town_Car               NA         NA      NA       NA
## MakeMazda 323                      NA         NA      NA       NA
## MakeMazda 626                      NA         NA      NA       NA
## MakeMazda Protege                  NA         NA      NA       NA
## MakeMercedes-Benz 190E             NA         NA      NA       NA
## MakeMercedes-Benz 300E             NA         NA      NA       NA
## MakeMercury Capri                  NA         NA      NA       NA
## MakeMercury Cougar                 NA         NA      NA       NA
## MakeMitsubishi Diamante            NA         NA      NA       NA
## MakeMitsubishi Mirage              NA         NA      NA       NA
## MakeNissan Altima                  NA         NA      NA       NA
## MakeNissan Maxima                  NA         NA      NA       NA
## MakeNissan Sentra                  NA         NA      NA       NA
## MakeOldsmobile Achieva             NA         NA      NA       NA
## MakeOldsmobile Cutlass_Ciera       NA         NA      NA       NA
## MakeOldsmobile Eighty-Eight        NA         NA      NA       NA
## MakePlymouth Laser                 NA         NA      NA       NA
## MakePontiac Bonneville             NA         NA      NA       NA
## MakePontiac Firebird               NA         NA      NA       NA
## MakePontiac Grand_Prix             NA         NA      NA       NA
## MakePontiac LeMans                 NA         NA      NA       NA
## MakePontiac Sunbird                NA         NA      NA       NA
## MakeSaab 900                       NA         NA      NA       NA
## MakeSaturn SL                      NA         NA      NA       NA
## MakeSubaru Justy                   NA         NA      NA       NA
## MakeSubaru Legacy                  NA         NA      NA       NA
## MakeSubaru Loyale                  NA         NA      NA       NA
## MakeSuzuki Swift                   NA         NA      NA       NA
## MakeToyota Camry                   NA         NA      NA       NA
## MakeToyota Celica                  NA         NA      NA       NA
## MakeToyota Tercel                  NA         NA      NA       NA
## MakeVolkswagen Corrado             NA         NA      NA       NA
## MakeVolkswagen Fox                 NA         NA      NA       NA
## MakeVolkswagen Passat              NA         NA      NA       NA
## MakeVolvo 240                      NA         NA      NA       NA
## MakeVolvo 850                      NA         NA      NA       NA
## 
## Residual standard error: NaN on 0 degrees of freedom
##   (11 observations deleted due to missingness)
## Multiple R-squared:      1,  Adjusted R-squared:    NaN 
## F-statistic:   NaN on 81 and 0 DF,  p-value: NA

Regression on numeric data

names(Cars93)
##  [1] "Manufacturer"       "Model"              "Type"              
##  [4] "Min.Price"          "Price"              "Max.Price"         
##  [7] "MPG.city"           "MPG.highway"        "AirBags"           
## [10] "DriveTrain"         "Cylinders"          "EngineSize"        
## [13] "Horsepower"         "RPM"                "Rev.per.mile"      
## [16] "Man.trans.avail"    "Fuel.tank.capacity" "Passengers"        
## [19] "Length"             "Wheelbase"          "Width"             
## [22] "Turn.circle"        "Rear.seat.room"     "Luggage.room"      
## [25] "Weight"             "Origin"             "Make"
Cars_new = Cars93[,c(4,5,6,7,8,13,14)]
fit<-lm(Price~.,data=Cars_new)
fit
## 
## Call:
## lm(formula = Price ~ ., data = Cars_new)
## 
## Coefficients:
## (Intercept)    Min.Price    Max.Price     MPG.city  MPG.highway  
##  -2.424e-02    5.010e-01    4.999e-01   -1.366e-04    8.368e-04  
##  Horsepower          RPM  
##  -9.402e-05   -1.293e-07
summary(fit)
## 
## Call:
## lm(formula = Price ~ ., data = Cars_new)
## 
## Residuals:
##       Min        1Q    Median        3Q       Max 
## -0.059180 -0.004209  0.002749  0.005789  0.056644 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept) -2.424e-02  3.521e-02  -0.689    0.493    
## Min.Price    5.010e-01  9.555e-04 524.319   <2e-16 ***
## Max.Price    4.999e-01  6.702e-04 745.820   <2e-16 ***
## MPG.city    -1.366e-04  1.891e-03  -0.072    0.943    
## MPG.highway  8.368e-04  1.768e-03   0.473    0.637    
## Horsepower  -9.402e-05  1.127e-04  -0.834    0.407    
## RPM         -1.293e-07  6.132e-06  -0.021    0.983    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.02942 on 86 degrees of freedom
## Multiple R-squared:      1,  Adjusted R-squared:      1 
## F-statistic: 1.653e+06 on 6 and 86 DF,  p-value: < 2.2e-16
step(fit) ###tells you the significant vars
## Start:  AIC=-649.16
## Price ~ Min.Price + Max.Price + MPG.city + MPG.highway + Horsepower + 
##     RPM
## 
##               Df Sum of Sq    RSS     AIC
## - RPM          1      0.00   0.07 -651.16
## - MPG.city     1      0.00   0.07 -651.15
## - MPG.highway  1      0.00   0.07 -650.92
## - Horsepower   1      0.00   0.08 -650.41
## <none>                       0.07 -649.16
## - Min.Price    1    237.87 237.94   99.37
## - Max.Price    1    481.30 481.37  164.90
## 
## Step:  AIC=-651.16
## Price ~ Min.Price + Max.Price + MPG.city + MPG.highway + Horsepower
## 
##               Df Sum of Sq    RSS     AIC
## - MPG.city     1      0.00   0.07 -653.15
## - MPG.highway  1      0.00   0.07 -652.91
## - Horsepower   1      0.00   0.08 -652.30
## <none>                       0.07 -651.16
## - Min.Price    1    240.37 240.45   98.34
## - Max.Price    1    486.96 487.03  163.98
## 
## Step:  AIC=-653.15
## Price ~ Min.Price + Max.Price + MPG.highway + Horsepower
## 
##               Df Sum of Sq    RSS     AIC
## - Horsepower   1      0.00   0.08 -654.29
## - MPG.highway  1      0.00   0.08 -654.18
## <none>                       0.07 -653.15
## - Min.Price    1    245.00 245.07   98.11
## - Max.Price    1    494.54 494.62  163.42
## 
## Step:  AIC=-654.29
## Price ~ Min.Price + Max.Price + MPG.highway
## 
##               Df Sum of Sq    RSS     AIC
## - MPG.highway  1      0.00   0.08 -654.49
## <none>                       0.08 -654.29
## - Min.Price    1    286.32 286.40  110.61
## - Max.Price    1    497.16 497.23  161.91
## 
## Step:  AIC=-654.49
## Price ~ Min.Price + Max.Price
## 
##             Df Sum of Sq    RSS     AIC
## <none>                     0.08 -654.49
## - Min.Price  1    313.24 313.32  116.96
## - Max.Price  1    497.22 497.30  159.92
## 
## Call:
## lm(formula = Price ~ Min.Price + Max.Price, data = Cars_new)
## 
## Coefficients:
## (Intercept)    Min.Price    Max.Price  
##   -0.005201     0.500354     0.499838
cor(Cars_new)###show the correlations among the values in the variables
##               Min.Price        Price   Max.Price   MPG.city MPG.highway
## Min.Price    1.00000000  0.970601402  0.90675608 -0.6228754  -0.5799658
## Price        0.97060140  1.000000000  0.98158027 -0.5945622  -0.5606804
## Max.Price    0.90675608  0.981580272  1.00000000 -0.5478109  -0.5225607
## MPG.city    -0.62287544 -0.594562163 -0.54781090  1.0000000   0.9439358
## MPG.highway -0.57996581 -0.560680362 -0.52256074  0.9439358   1.0000000
## Horsepower   0.80244412  0.788217578  0.74444475 -0.6726362  -0.6190437
## RPM         -0.04259816 -0.004954931  0.02501478  0.3630451   0.3134687
##              Horsepower          RPM
## Min.Price    0.80244412 -0.042598158
## Price        0.78821758 -0.004954931
## Max.Price    0.74444475  0.025014782
## MPG.city    -0.67263615  0.363045129
## MPG.highway -0.61904368  0.313468728
## Horsepower   1.00000000  0.036688212
## RPM          0.03668821  1.000000000
cov(Cars_new) ###using 
##              Min.Price     Price Max.Price   MPG.city MPG.highway
## Min.Price     76.49302  81.99801  87.47720  -30.61497   -27.04464
## Price         81.99801  93.30458 104.58534  -32.27532   -28.87584
## Max.Price     87.47720 104.58534 121.67098  -33.95830   -30.73252
## MPG.city     -30.61497 -32.27532 -33.95830   31.58228    28.28343
## MPG.highway  -27.04464 -28.87584 -30.73252   28.28343    28.42730
## Horsepower   367.57405 398.76473 430.07590 -197.97990  -172.86547
## RPM         -222.32118 -28.56066 164.65288 1217.47896   997.33520
##             Horsepower          RPM
## Min.Price     367.5741   -222.32118
## Price         398.7647    -28.56066
## Max.Price     430.0759    164.65288
## MPG.city     -197.9799   1217.47896
## MPG.highway  -172.8655    997.33520
## Horsepower   2743.0788   1146.63394
## RPM          1146.6339 356088.70968
Cars_new$predicted_price <- predict(fit,Cars_new)
View(Cars_new)
Test <-cbind(Cars_new$Price, Cars_new$predicted_price)
View(Test)

Test1<-cbind(Cars_new$Price, Cars_new$predicted_price, Cars_new$Price-Cars_new$predicted_price)
View(Test1)
summary(Test1)
##        V1              V2               V3           
##  Min.   : 7.40   Min.   : 7.399   Min.   :-0.059180  
##  1st Qu.:12.20   1st Qu.:12.196   1st Qu.:-0.004209  
##  Median :17.70   Median :17.692   Median : 0.002749  
##  Mean   :19.51   Mean   :19.510   Mean   : 0.000000  
##  3rd Qu.:23.30   3rd Qu.:23.297   3rd Qu.: 0.005789  
##  Max.   :61.90   Max.   :61.907   Max.   : 0.056644
####where v1 - price, v2 - predicted-price, v3- is error (difference between v1,v3)

fit1<-lm(formula=log(Price)~.,data=Cars_new)#transformation
fit1
## 
## Call:
## lm(formula = log(Price) ~ ., data = Cars_new)
## 
## Coefficients:
##     (Intercept)        Min.Price        Max.Price         MPG.city  
##       2.345e+00        2.104e-02        1.665e-02       -2.098e-02  
##     MPG.highway       Horsepower              RPM  predicted_price  
##       6.128e-03        6.014e-04        1.234e-08               NA
summary(fit1)
## 
## Call:
## lm(formula = log(Price) ~ ., data = Cars_new)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.35811 -0.04295  0.02385  0.06746  0.24633 
## 
## Coefficients: (1 not defined because of singularities)
##                   Estimate Std. Error t value Pr(>|t|)    
## (Intercept)      2.345e+00  1.240e-01  18.917  < 2e-16 ***
## Min.Price        2.104e-02  3.364e-03   6.254 1.49e-08 ***
## Max.Price        1.665e-02  2.360e-03   7.056 4.11e-10 ***
## MPG.city        -2.098e-02  6.657e-03  -3.152  0.00223 ** 
## MPG.highway      6.128e-03  6.226e-03   0.984  0.32772    
## Horsepower       6.014e-04  3.969e-04   1.515  0.13337    
## RPM              1.234e-08  2.159e-05   0.001  0.99955    
## predicted_price         NA         NA      NA       NA    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.1036 on 86 degrees of freedom
## Multiple R-squared:  0.9515, Adjusted R-squared:  0.9481 
## F-statistic: 281.2 on 6 and 86 DF,  p-value: < 2.2e-16
hist(Cars_new$Price-Cars_new$predicted_price)

plot(Cars_new$Price-Cars_new$predicted_price,Cars_new$predicted_price)

cor(Cars_new$Price-Cars_new$predicted_price,Cars_new$predicted_price)
## [1] 3.188682e-13

Prediction process in Regression Model

Sample data for Train and Test

to find the number of observations we use nrow(Cars93)

data(Cars93)
## Warning in data(Cars93): data set 'Cars93' not found
samp_size<-floor(0.75 * nrow(Cars93))
data(Adult)
## Warning in data(Adult): data set 'Adult' not found