2. Entender la base de datos
##
## 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
## Observation Dist_Taxi Dist_Market Dist_Hospital
## Min. : 1.0 Min. : 146 Min. : 1666 Min. : 3227
## 1st Qu.:237.0 1st Qu.: 6477 1st Qu.: 9367 1st Qu.:11302
## Median :469.0 Median : 8228 Median :11149 Median :13189
## Mean :468.4 Mean : 8235 Mean :11022 Mean :13091
## 3rd Qu.:700.0 3rd Qu.: 9939 3rd Qu.:12675 3rd Qu.:14855
## Max. :932.0 Max. :20662 Max. :20945 Max. :23294
##
## Carpet Builtup Parking City_Category
## Min. : 775 Min. : 932 Length:905 Length:905
## 1st Qu.: 1317 1st Qu.: 1579 Class :character Class :character
## Median : 1478 Median : 1774 Mode :character Mode :character
## Mean : 1511 Mean : 1794
## 3rd Qu.: 1654 3rd Qu.: 1985
## Max. :24300 Max. :12730
## NA's :7
## Rainfall House_Price
## Min. :-110.0 Min. : 1492000
## 1st Qu.: 600.0 1st Qu.: 4623000
## Median : 780.0 Median : 5860000
## Mean : 786.9 Mean : 6083992
## 3rd Qu.: 970.0 3rd Qu.: 7200000
## Max. :1560.0 Max. :150000000
##
count(df, Parking, sort=TRUE)
## Parking n
## 1 Open 355
## 2 Not Provided 225
## 3 Covered 184
## 4 No Parking 141
count(df, City_Category, sort=TRUE)
## City_Category n
## 1 CAT B 351
## 2 CAT A 320
## 3 CAT C 234
#Cuantos NA tenemos en la base de datos?
sum(is.na(df))
## [1] 7
# Cuantos NA tengo por variable?
sapply(df, function(x) sum(is.na(x)))
## Observation Dist_Taxi Dist_Market Dist_Hospital Carpet
## 0 0 0 0 7
## Builtup Parking City_Category Rainfall House_Price
## 0 0 0 0 0
# Eliminar NA
df <- na.omit(df)
#Eliminar el registro del precio atípico
df <- df[df$House_Price<12000000,]
# Eliminar el registro de lluvia atípico
df <- df[df$Rainfall>=0,]
#Gráficas
boxplot(df$House_Price, horizontal=TRUE)

3. Generar la regresión lineal
regresion <- lm(House_Price ~ Dist_Taxi+Dist_Market + Dist_Hospital + Carpet + Builtup + Parking + City_Category + Rainfall , data=df)
summary(regresion)
##
## Call:
## lm(formula = House_Price ~ Dist_Taxi + Dist_Market + Dist_Hospital +
## Carpet + Builtup + Parking + City_Category + Rainfall, data = df)
##
## Residuals:
## Min 1Q Median 3Q Max
## -3572009 -800792 -65720 761534 4401585
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 5.599e+06 3.672e+05 15.246 < 2e-16 ***
## Dist_Taxi 3.009e+01 2.682e+01 1.122 0.2622
## Dist_Market 1.285e+01 2.081e+01 0.618 0.5370
## Dist_Hospital 4.864e+01 3.008e+01 1.617 0.1062
## Carpet -7.997e+02 3.476e+03 -0.230 0.8181
## Builtup 1.339e+03 2.901e+03 0.462 0.6444
## ParkingNo Parking -6.040e+05 1.389e+05 -4.348 1.53e-05 ***
## ParkingNot Provided -4.924e+05 1.235e+05 -3.988 7.22e-05 ***
## ParkingOpen -2.632e+05 1.126e+05 -2.338 0.0196 *
## City_CategoryCAT B -1.877e+06 9.598e+04 -19.554 < 2e-16 ***
## City_CategoryCAT C -2.890e+06 1.059e+05 -27.300 < 2e-16 ***
## Rainfall -1.175e+02 1.550e+02 -0.758 0.4484
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1222000 on 884 degrees of freedom
## Multiple R-squared: 0.5007, Adjusted R-squared: 0.4945
## F-statistic: 80.58 on 11 and 884 DF, p-value: < 2.2e-16
4. Construir un modelo predictivo
datos <- data.frame(Dist_Taxi=8278,Dist_Market=16251, Dist_Hospital=13857, Carpet = 1455, Builtup = 1764, Parking="Covered",City_Category = "CAT A", Rainfall= 390)
predict(regresion,datos)
## 1
## 7883860