Una red neuronal artificial (ANN) modela la relación entre un conjunto de entradas y una salida, resolviendo un problema de aprendizaje.

Algunos ejemplos de aplicación de ANN son:

  • La recomendación de contenido de Netflix.
  • El feed de Instagram.
  • Determinar el número escrito a mano.

Ejercicio 1. ¿Pasé la materia?

1. Instalar paquetes y llamar librerías

# install.packages("neuralnet")
library("neuralnet")
## Warning: package 'neuralnet' was built under R version 4.3.2

2. Obtener datos

examen <- c(20,10,30,20,80,30)
proyecto <- c(90,20,40,50,50,80)
estatus <- c(1,0,0,0,0,1)

df1 <- data.frame(examen, proyecto, estatus)

3. Crear Red Neuronal

set.seed(123)
rn1 <- neuralnet(estatus ~., data = df1)
plot(rn1, rep = "best")

## 4. Predecir Resultados Futuros

# Importante que las columnas estén colocadas en las mismas posiciones
prueba_examen <- c(30,40,85)
prueba_proyecto <- c(85,50,40)
prueba1 <- data.frame(prueba_examen,prueba_proyecto)
prediccion <- compute(rn1, prueba1)
probabilidad <- prediccion$net.result
resultado <-- ifelse(probabilidad>0.5, 1, 0)
resultado
##      [,1]
## [1,]   -1
## [2,]    0
## [3,]    0

Ejercicio 2 Cancer de Mama

1. Instalar paquetes y llamar librerías

#install.packages("neuralnet")
library("neuralnet")
library(readxl)
## Warning: package 'readxl' was built under R version 4.3.1

2. Obtener datos

df2 <- read_excel("C:\\Users\\memil\\OneDrive\\Desktop\\aaTecDeMonterrey\\6to Semestre\\cancer_de_mama.xlsx")
df2$diagnosis <- ifelse(df2$diagnosis == "M", 1, 0)

3. Crear Red Neuronal

set.seed(123)
rn2 <- neuralnet(diagnosis ~., data = df2)
plot(rn2, rep = "best")

summary(df2)
##    diagnosis       radius_mean      texture_mean   perimeter_mean  
##  Min.   :0.0000   Min.   : 6.981   Min.   : 9.71   Min.   : 43.79  
##  1st Qu.:0.0000   1st Qu.:11.700   1st Qu.:16.17   1st Qu.: 75.17  
##  Median :0.0000   Median :13.370   Median :18.84   Median : 86.24  
##  Mean   :0.3726   Mean   :14.127   Mean   :19.29   Mean   : 91.97  
##  3rd Qu.:1.0000   3rd Qu.:15.780   3rd Qu.:21.80   3rd Qu.:104.10  
##  Max.   :1.0000   Max.   :28.110   Max.   :39.28   Max.   :188.50  
##    area_mean      smoothness_mean   compactness_mean  concavity_mean   
##  Min.   : 143.5   Min.   :0.05263   Min.   :0.01938   Min.   :0.00000  
##  1st Qu.: 420.3   1st Qu.:0.08637   1st Qu.:0.06492   1st Qu.:0.02956  
##  Median : 551.1   Median :0.09587   Median :0.09263   Median :0.06154  
##  Mean   : 654.9   Mean   :0.09636   Mean   :0.10434   Mean   :0.08880  
##  3rd Qu.: 782.7   3rd Qu.:0.10530   3rd Qu.:0.13040   3rd Qu.:0.13070  
##  Max.   :2501.0   Max.   :0.16340   Max.   :0.34540   Max.   :0.42680  
##  concave_points_mean symmetry_mean    fractal_dimension_mean   radius_se     
##  Min.   :0.00000     Min.   :0.1060   Min.   :0.04996        Min.   :0.1115  
##  1st Qu.:0.02031     1st Qu.:0.1619   1st Qu.:0.05770        1st Qu.:0.2324  
##  Median :0.03350     Median :0.1792   Median :0.06154        Median :0.3242  
##  Mean   :0.04892     Mean   :0.1812   Mean   :0.06280        Mean   :0.4052  
##  3rd Qu.:0.07400     3rd Qu.:0.1957   3rd Qu.:0.06612        3rd Qu.:0.4789  
##  Max.   :0.20120     Max.   :0.3040   Max.   :0.09744        Max.   :2.8730  
##    texture_se      perimeter_se       area_se        smoothness_se     
##  Min.   :0.3602   Min.   : 0.757   Min.   :  6.802   Min.   :0.001713  
##  1st Qu.:0.8339   1st Qu.: 1.606   1st Qu.: 17.850   1st Qu.:0.005169  
##  Median :1.1080   Median : 2.287   Median : 24.530   Median :0.006380  
##  Mean   :1.2169   Mean   : 2.866   Mean   : 40.337   Mean   :0.007041  
##  3rd Qu.:1.4740   3rd Qu.: 3.357   3rd Qu.: 45.190   3rd Qu.:0.008146  
##  Max.   :4.8850   Max.   :21.980   Max.   :542.200   Max.   :0.031130  
##  compactness_se      concavity_se     concave_points_se   symmetry_se      
##  Min.   :0.002252   Min.   :0.00000   Min.   :0.000000   Min.   :0.007882  
##  1st Qu.:0.013080   1st Qu.:0.01509   1st Qu.:0.007638   1st Qu.:0.015160  
##  Median :0.020450   Median :0.02589   Median :0.010930   Median :0.018730  
##  Mean   :0.025478   Mean   :0.03189   Mean   :0.011796   Mean   :0.020542  
##  3rd Qu.:0.032450   3rd Qu.:0.04205   3rd Qu.:0.014710   3rd Qu.:0.023480  
##  Max.   :0.135400   Max.   :0.39600   Max.   :0.052790   Max.   :0.078950  
##  fractal_dimension_se  radius_worst   texture_worst   perimeter_worst 
##  Min.   :0.0008948    Min.   : 7.93   Min.   :12.02   Min.   : 50.41  
##  1st Qu.:0.0022480    1st Qu.:13.01   1st Qu.:21.08   1st Qu.: 84.11  
##  Median :0.0031870    Median :14.97   Median :25.41   Median : 97.66  
##  Mean   :0.0037949    Mean   :16.27   Mean   :25.68   Mean   :107.26  
##  3rd Qu.:0.0045580    3rd Qu.:18.79   3rd Qu.:29.72   3rd Qu.:125.40  
##  Max.   :0.0298400    Max.   :36.04   Max.   :49.54   Max.   :251.20  
##    area_worst     smoothness_worst  compactness_worst concavity_worst 
##  Min.   : 185.2   Min.   :0.07117   Min.   :0.02729   Min.   :0.0000  
##  1st Qu.: 515.3   1st Qu.:0.11660   1st Qu.:0.14720   1st Qu.:0.1145  
##  Median : 686.5   Median :0.13130   Median :0.21190   Median :0.2267  
##  Mean   : 880.6   Mean   :0.13237   Mean   :0.25427   Mean   :0.2722  
##  3rd Qu.:1084.0   3rd Qu.:0.14600   3rd Qu.:0.33910   3rd Qu.:0.3829  
##  Max.   :4254.0   Max.   :0.22260   Max.   :1.05800   Max.   :1.2520  
##  concave_points_worst symmetry_worst   fractal_dimension_worst
##  Min.   :0.00000      Min.   :0.1565   Min.   :0.05504        
##  1st Qu.:0.06493      1st Qu.:0.2504   1st Qu.:0.07146        
##  Median :0.09993      Median :0.2822   Median :0.08004        
##  Mean   :0.11461      Mean   :0.2901   Mean   :0.08395        
##  3rd Qu.:0.16140      3rd Qu.:0.3179   3rd Qu.:0.09208        
##  Max.   :0.29100      Max.   :0.6638   Max.   :0.20750

4. Predecir Resultados Futuros

# Importante que las columnas estén colocadas en las mismas posiciones
prueba_examen <- c(30,40,85)
prueba_proyecto <- c(85,50,40)
prueba1 <- data.frame(prueba_examen,prueba_proyecto)
prediccion <- compute(rn1, prueba1)
probabilidad <- prediccion$net.result
resultado <-- ifelse(probabilidad>0.5, 1, 0)
resultado
##      [,1]
## [1,]   -1
## [2,]    0
## [3,]    0