#install.packages("caret")
library(caret)
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 #install.packages("tidyverse")
library(tidyverse)
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df <- read.csv("C:\\Users\\sams\\Downloads\\heart.csv")
# Explorar datos
summary(df)
##       age             sex               cp            trestbps    
##  Min.   :29.00   Min.   :0.0000   Min.   :0.0000   Min.   : 94.0  
##  1st Qu.:48.00   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:120.0  
##  Median :56.00   Median :1.0000   Median :1.0000   Median :130.0  
##  Mean   :54.43   Mean   :0.6956   Mean   :0.9424   Mean   :131.6  
##  3rd Qu.:61.00   3rd Qu.:1.0000   3rd Qu.:2.0000   3rd Qu.:140.0  
##  Max.   :77.00   Max.   :1.0000   Max.   :3.0000   Max.   :200.0  
##       chol          fbs            restecg          thalach     
##  Min.   :126   Min.   :0.0000   Min.   :0.0000   Min.   : 71.0  
##  1st Qu.:211   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:132.0  
##  Median :240   Median :0.0000   Median :1.0000   Median :152.0  
##  Mean   :246   Mean   :0.1493   Mean   :0.5298   Mean   :149.1  
##  3rd Qu.:275   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:166.0  
##  Max.   :564   Max.   :1.0000   Max.   :2.0000   Max.   :202.0  
##      exang           oldpeak          slope             ca        
##  Min.   :0.0000   Min.   :0.000   Min.   :0.000   Min.   :0.0000  
##  1st Qu.:0.0000   1st Qu.:0.000   1st Qu.:1.000   1st Qu.:0.0000  
##  Median :0.0000   Median :0.800   Median :1.000   Median :0.0000  
##  Mean   :0.3366   Mean   :1.072   Mean   :1.385   Mean   :0.7541  
##  3rd Qu.:1.0000   3rd Qu.:1.800   3rd Qu.:2.000   3rd Qu.:1.0000  
##  Max.   :1.0000   Max.   :6.200   Max.   :2.000   Max.   :4.0000  
##       thal           target      
##  Min.   :0.000   Min.   :0.0000  
##  1st Qu.:2.000   1st Qu.:0.0000  
##  Median :2.000   Median :1.0000  
##  Mean   :2.324   Mean   :0.5132  
##  3rd Qu.:3.000   3rd Qu.:1.0000  
##  Max.   :3.000   Max.   :1.0000
str(df)
## 'data.frame':    1025 obs. of  14 variables:
##  $ age     : int  52 53 70 61 62 58 58 55 46 54 ...
##  $ sex     : int  1 1 1 1 0 0 1 1 1 1 ...
##  $ cp      : int  0 0 0 0 0 0 0 0 0 0 ...
##  $ trestbps: int  125 140 145 148 138 100 114 160 120 122 ...
##  $ chol    : int  212 203 174 203 294 248 318 289 249 286 ...
##  $ fbs     : int  0 1 0 0 1 0 0 0 0 0 ...
##  $ restecg : int  1 0 1 1 1 0 2 0 0 0 ...
##  $ thalach : int  168 155 125 161 106 122 140 145 144 116 ...
##  $ exang   : int  0 1 1 0 0 0 0 1 0 1 ...
##  $ oldpeak : num  1 3.1 2.6 0 1.9 1 4.4 0.8 0.8 3.2 ...
##  $ slope   : int  2 0 0 2 1 1 0 1 2 1 ...
##  $ ca      : int  2 0 0 1 3 0 3 1 0 2 ...
##  $ thal    : int  3 3 3 3 2 2 1 3 3 2 ...
##  $ target  : int  0 0 0 0 0 1 0 0 0 0 ...
df <- df[, c("target","age","sex","cp","thalach","oldpeak")]

# Eliminar valores faltantes
df <- na.omit(df)

# Convertir variable objetivo a factor
df$target <- as.factor(df$target)

# Convertir variables categóricas
df$sex <- as.factor(df$sex)
df$cp <- as.factor(df$cp)

str(df)
## 'data.frame':    1025 obs. of  6 variables:
##  $ target : Factor w/ 2 levels "0","1": 1 1 1 1 1 2 1 1 1 1 ...
##  $ age    : int  52 53 70 61 62 58 58 55 46 54 ...
##  $ sex    : Factor w/ 2 levels "0","1": 2 2 2 2 1 1 2 2 2 2 ...
##  $ cp     : Factor w/ 4 levels "0","1","2","3": 1 1 1 1 1 1 1 1 1 1 ...
##  $ thalach: int  168 155 125 161 106 122 140 145 144 116 ...
##  $ oldpeak: num  1 3.1 2.6 0 1.9 1 4.4 0.8 0.8 3.2 ...
modelo <- glm(target ~ ., data=df, family=binomial)

summary(modelo)
## 
## Call:
## glm(formula = target ~ ., family = binomial, data = df)
## 
## Coefficients:
##              Estimate Std. Error z value Pr(>|z|)    
## (Intercept) -0.359747   1.056669  -0.340 0.733515    
## age         -0.039298   0.010644  -3.692 0.000222 ***
## sex1        -1.844887   0.208584  -8.845  < 2e-16 ***
## cp1          1.732941   0.256082   6.767 1.31e-11 ***
## cp2          2.204962   0.212669  10.368  < 2e-16 ***
## cp3          2.288578   0.314506   7.277 3.42e-13 ***
## thalach      0.023697   0.004608   5.143 2.71e-07 ***
## oldpeak     -0.754388   0.092440  -8.161 3.33e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 1420.24  on 1024  degrees of freedom
## Residual deviance:  856.15  on 1017  degrees of freedom
## AIC: 872.15
## 
## Number of Fisher Scoring iterations: 5
nueva_persona <- data.frame(
  age = 62,
  sex = factor(0),
  cp = factor(1),
  thalach = 138,
  oldpeak = 1.7
)

riesgo <- predict(modelo, newdata = nueva_persona, type = "response")

cbind(nueva_persona, Probabilidad_Enfermedad = riesgo)
##   age sex cp thalach oldpeak Probabilidad_Enfermedad
## 1  62   0  1     138     1.7               0.7159638

#Conclusión Al revisar lo que arrojó el análisis, se puede notar que el modelo sí aporta información relevante para identificar la probabilidad de padecer enfermedad cardíaca. Varias de las variables incluidas tienen un peso importante dentro de la estimación, especialmente el tipo de dolor en el pecho, el sexo de la persona y el valor de oldpeak, que influyen de manera clara en el resultado final.