Contexto

Estos datos son el resiltado de una análisis químico de vinos cultivados en la misma región de Italia derivados de tres cultivares diferentes.

El análisis determinó las cantidades de 13 componentes que se encuentran en cada uno de los tres tipos de vinos.

Paso 1. Instalar paquetes y llamar librerías

#install.packages("data.table")
library(cluster) # Librería para la realización de clusters
library(ggplot2) # Librería para la visualización de datos 
library(data.table) # 
library(factoextra) # librería para graficar cluster
## Welcome! Want to learn more? See two factoextra-related books at https://goo.gl/ve3WBa
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:data.table':
## 
##     between, first, last
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(readr)

Paso 2. Obtener los datos

df = read_csv("wine.csv")
# Conocer la naturalidad de los datos
summary(df)
##     Alcohol        Malic_Acid         Ash         Ash_Alcanity  
##  Min.   :11.03   Min.   :0.740   Min.   :1.360   Min.   :10.60  
##  1st Qu.:12.36   1st Qu.:1.603   1st Qu.:2.210   1st Qu.:17.20  
##  Median :13.05   Median :1.865   Median :2.360   Median :19.50  
##  Mean   :13.00   Mean   :2.336   Mean   :2.367   Mean   :19.49  
##  3rd Qu.:13.68   3rd Qu.:3.083   3rd Qu.:2.558   3rd Qu.:21.50  
##  Max.   :14.83   Max.   :5.800   Max.   :3.230   Max.   :30.00  
##    Magnesium      Total_Phenols     Flavanoids    Nonflavanoid_Phenols
##  Min.   : 70.00   Min.   :0.980   Min.   :0.340   Min.   :0.1300      
##  1st Qu.: 88.00   1st Qu.:1.742   1st Qu.:1.205   1st Qu.:0.2700      
##  Median : 98.00   Median :2.355   Median :2.135   Median :0.3400      
##  Mean   : 99.74   Mean   :2.295   Mean   :2.029   Mean   :0.3619      
##  3rd Qu.:107.00   3rd Qu.:2.800   3rd Qu.:2.875   3rd Qu.:0.4375      
##  Max.   :162.00   Max.   :3.880   Max.   :5.080   Max.   :0.6600      
##  Proanthocyanins Color_Intensity       Hue             OD280      
##  Min.   :0.410   Min.   : 1.280   Min.   :0.4800   Min.   :1.270  
##  1st Qu.:1.250   1st Qu.: 3.220   1st Qu.:0.7825   1st Qu.:1.938  
##  Median :1.555   Median : 4.690   Median :0.9650   Median :2.780  
##  Mean   :1.591   Mean   : 5.058   Mean   :0.9574   Mean   :2.612  
##  3rd Qu.:1.950   3rd Qu.: 6.200   3rd Qu.:1.1200   3rd Qu.:3.170  
##  Max.   :3.580   Max.   :13.000   Max.   :1.7100   Max.   :4.000  
##     Proline      
##  Min.   : 278.0  
##  1st Qu.: 500.5  
##  Median : 673.5  
##  Mean   : 746.9  
##  3rd Qu.: 985.0  
##  Max.   :1680.0

Paso 3. Cantidad de grupos

df_escalada = scale(df)

grupos = 3 

Paso 4. Generar los segmentos

segmentos = kmeans(df_escalada,grupos)
segmentos
## K-means clustering with 3 clusters of sizes 62, 51, 65
## 
## Cluster means:
##      Alcohol Malic_Acid        Ash Ash_Alcanity   Magnesium Total_Phenols
## 1  0.8328826 -0.3029551  0.3636801   -0.6084749  0.57596208    0.88274724
## 2  0.1644436  0.8690954  0.1863726    0.5228924 -0.07526047   -0.97657548
## 3 -0.9234669 -0.3929331 -0.4931257    0.1701220 -0.49032869   -0.07576891
##    Flavanoids Nonflavanoid_Phenols Proanthocyanins Color_Intensity        Hue
## 1  0.97506900          -0.56050853      0.57865427       0.1705823  0.4726504
## 2 -1.21182921           0.72402116     -0.77751312       0.9388902 -1.1615122
## 3  0.02075402          -0.03343924      0.05810161      -0.8993770  0.4605046
##        OD280    Proline
## 1  0.7770551  1.1220202
## 2 -1.2887761 -0.4059428
## 3  0.2700025 -0.7517257
## 
## Clustering vector:
##   [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
##  [38] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 2 3 3 3 3 3 3 3 3 3 3 3 1
##  [75] 3 3 3 3 3 3 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
## [112] 3 3 3 3 3 3 3 2 3 3 1 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
## [149] 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
## 
## Within cluster sum of squares by cluster:
## [1] 385.6983 326.3537 558.6971
##  (between_SS / total_SS =  44.8 %)
## 
## Available components:
## 
## [1] "cluster"      "centers"      "totss"        "withinss"     "tot.withinss"
## [6] "betweenss"    "size"         "iter"         "ifault"

Paso 5. Asignar el grupo al que pertenece cada observación

asignacion = cbind(df, cluster = segmentos$cluster)
#asignacion

Paso 6. Graficar los clusters

fviz_cluster(segmentos, data = df_escalada)

Paso 7. Optimizar la cantidad de grupos

# La cantidad optima de grupos corresponde al punto más alto de la siguiente gráfica
set.seed(123)
optimizacion = clusGap(df_escalada, FUN = kmeans, nstart = 1, K.max = 10)
plot(optimizacion, xlab="Número de cluster k")

Paso 8. Análisis de clasificación del cluster

# Grouping by 'assignation$cluster' and calculating mean of all numeric variables
analisis <- asignacion %>%
  group_by(asignacion$cluster) %>%
  summarise(across(where(is.numeric), mean, na.rm = TRUE))
## Warning: There was 1 warning in `summarise()`.
## ℹ In argument: `across(where(is.numeric), mean, na.rm = TRUE)`.
## ℹ In group 1: `asignacion$cluster = 1`.
## Caused by warning:
## ! The `...` argument of `across()` is deprecated as of dplyr 1.1.0.
## Supply arguments directly to `.fns` through an anonymous function instead.
## 
##   # Previously
##   across(a:b, mean, na.rm = TRUE)
## 
##   # Now
##   across(a:b, \(x) mean(x, na.rm = TRUE))
# Display the result
print(analisis)
## # A tibble: 3 × 15
##   `asignacion$cluster` Alcohol Malic_Acid   Ash Ash_Alcanity Magnesium
##                  <int>   <dbl>      <dbl> <dbl>        <dbl>     <dbl>
## 1                    1    13.7       2.00  2.47         17.5     108. 
## 2                    2    13.1       3.31  2.42         21.2      98.7
## 3                    3    12.3       1.90  2.23         20.1      92.7
## # ℹ 9 more variables: Total_Phenols <dbl>, Flavanoids <dbl>,
## #   Nonflavanoid_Phenols <dbl>, Proanthocyanins <dbl>, Color_Intensity <dbl>,
## #   Hue <dbl>, OD280 <dbl>, Proline <dbl>, cluster <dbl>

Conclusion

la segmentacion o clusters es un algoritmno útil para identificar ell cultivar correspondiente a cada vino