Importación de Datos y Solución Rotada

library(readr)
datos_ejercicio <- read_table2("http://halweb.uc3m.es/esp/Personal/personas/agrane/libro/ficheros_datos/capitulo_7/datos_prob_7_3.txt",col_names = FALSE)

Solución Rotada

library(psych)
modelo_4<-principal(r = datos_ejercicio,nfactors = 4,covar = FALSE,rotate = "varimax")
modelo_4$loadings
## 
## Loadings:
##    RC1    RC2    RC4    RC3   
## X1 -0.218 -0.102 -0.900 -0.143
## X2 -0.118 -0.937 -0.163  0.179
## X3  0.761         0.447       
## X4  0.216         0.113  0.960
## X5  0.382  0.366  0.715       
## X6         0.951  0.118       
## X7  0.877  0.152  0.287  0.269
## X8  0.971                0.121
## 
##                  RC1   RC2   RC4   RC3
## SS loadings    2.549 1.954 1.667 1.071
## Proportion Var 0.319 0.244 0.208 0.134
## Cumulative Var 0.319 0.563 0.771 0.905

Quedan dentro del factor 1: X3, X7 y X8

Método CRITIC

Normalización de datos y cálculos

#Funciones para normalizar los datos
norm_directa <- function(x){
  return((x-min(x)) / (max(x)-min(x)))
}
norm_inverza <- function(x){
  return((max(x)-x) / (max(x)-min(x)))
}
# Normalización de los datos
library(dplyr)
datos_ejercicio %>% dplyr::select(X3,X7,X8) %>% dplyr::transmute(X3=norm_directa(X3),X7=norm_directa(X7), X8=norm_inverza(X8)) ->data_factor_1
print(data_factor_1)
## # A tibble: 18 x 3
##        X3      X7    X8
##     <dbl>   <dbl> <dbl>
##  1 0.983  0.768   0.353
##  2 0.55   0.165   0.765
##  3 0.483  0       1    
##  4 1      0.744   0.118
##  5 0.0333 0.00478 1    
##  6 0.517  0.175   0.941
##  7 0.283  0.0215  1    
##  8 0.867  0.440   0.706
##  9 0.333  0.215   0.941
## 10 0      0.0478  1    
## 11 0.2    0.0191  1    
## 12 0.5    0.670   0.706
## 13 0.867  0.184   0.824
## 14 0.3    0.110   1    
## 15 0.0667 0.0335  1    
## 16 0.3    0.445   0.647
## 17 0.533  0.309   0.882
## 18 0.767  1       0
#Cálculo de las desviaciones estándar de cada variable

data_factor_1 %>% dplyr::summarise(S3=sd(X3),S7=sd(X7),S8=sd(X8))-> sd_vector
print(sd_vector)
## # A tibble: 1 x 3
##      S3    S7    S8
##   <dbl> <dbl> <dbl>
## 1 0.318 0.311 0.312
#Cálculo de la matriz de correlación

cor(data_factor_1)->mat_R_F1
print(mat_R_F1)
##            X3         X7         X8
## X3  1.0000000  0.7060802 -0.7251117
## X7  0.7060802  1.0000000 -0.9346464
## X8 -0.7251117 -0.9346464  1.0000000
#Cálculo de los ponderadores brutos
1-mat_R_F1->sum_data
colSums(sum_data)->sum_vector
sd_vector*sum_vector->vj
print(vj)
##          S3       S7       S8
## 1 0.6419218 0.692672 1.143666
#Cálculo de los ponderadores netos

vj/sum(vj)->wj
print(wj)
##          S3        S7        S8
## 1 0.2590212 0.2794994 0.4614794
#Ponderadores:
print(round(wj*100,2))
##     S3    S7    S8
## 1 25.9 27.95 46.15

Método de Entropía

#Normalización de los datos
datos_ejercicio %>% dplyr::select(X3,X7,X8)->data_norm
apply(data_norm,2,prop.table)->data_norm
print(data_norm)
##               X3          X7         X8
##  [1,] 0.10166920 0.131305352 0.13636364
##  [2,] 0.06221548 0.034270312 0.05681818
##  [3,] 0.05614568 0.007701194 0.01136364
##  [4,] 0.10318665 0.127454755 0.18181818
##  [5,] 0.01517451 0.008471313 0.01136364
##  [6,] 0.05918058 0.035810551 0.02272727
##  [7,] 0.03793627 0.011166731 0.01136364
##  [8,] 0.09104704 0.078552176 0.06818182
##  [9,] 0.04248862 0.042356565 0.02272727
## [10,] 0.01213961 0.015402387 0.01136364
## [11,] 0.03034901 0.010781671 0.01136364
## [12,] 0.05766313 0.115517905 0.06818182
## [13,] 0.09104704 0.037350789 0.04545455
## [14,] 0.03945372 0.025413939 0.01136364
## [15,] 0.01820941 0.013092029 0.01136364
## [16,] 0.03945372 0.079322295 0.07954545
## [17,] 0.06069803 0.057373893 0.03409091
## [18,] 0.08194234 0.168656142 0.20454545
#Fórmula de entropía
entropy<-function(x){
  return(x*log(x))
}
apply(data_norm,2,entropy)->data_norm_2
print(data_norm_2)
##                X3          X7          X8
##  [1,] -0.23241892 -0.26658003 -0.27169502
##  [2,] -0.17278181 -0.11561007 -0.16294880
##  [3,] -0.16168863 -0.03747693 -0.05087883
##  [4,] -0.23435914 -0.26255601 -0.30995420
##  [5,] -0.06355294 -0.04041723 -0.05087883
##  [6,] -0.16731307 -0.11923168 -0.08600431
##  [7,] -0.12412169 -0.05019240 -0.05087883
##  [8,] -0.21818321 -0.19983612 -0.18310755
##  [9,] -0.13420111 -0.13391587 -0.08600431
## [10,] -0.05355122 -0.06427775 -0.05087883
## [11,] -0.10606954 -0.04883998 -0.05087883
## [12,] -0.16452082 -0.24932573 -0.18310755
## [13,] -0.21818321 -0.12278703 -0.14050193
## [14,] -0.12753915 -0.09333161 -0.05087883
## [15,] -0.07294355 -0.05676379 -0.05087883
## [16,] -0.12753915 -0.20102142 -0.20136348
## [17,] -0.17006641 -0.16398410 -0.11518379
## [18,] -0.20499838 -0.30018994 -0.32460649
#Número de variables en el factor:
ncol(data_norm)->m
#Constante de entropía:
-1/log(m)->K
print(K)
## [1] -0.9102392
#Cálculo de las entropías
K*colSums(data_norm_2)->Ej
print(Ej)
##       X3       X7       X8 
## 2.506828 2.299572 2.203352
#Cálculo de las especificidades:
1-Ej->vj
print(vj)
##        X3        X7        X8 
## -1.506828 -1.299572 -1.203352
#Cálculo de los ponderadores:
prop.table(vj)->wj #es igual a usar vj/sum(vj)
print(wj)
##        X3        X7        X8 
## 0.3757909 0.3241028 0.3001063