library(arules)
library(arulesViz)

# Load the data set
data(Groceries)

itemFrequencyPlot(Groceries,topN=20,type="absolute")

# Encontrar Regras com suporte ao menos 0.001 e confianca 0.8:
# obs: maxlen=3: no máximo 3 variáveis do lado esquedo
regras=apriori(Groceries, parameter = list(supp=0.005, conf=0.5,maxlen=3))

options(digits=2) # algarismos significativos

length(regras) # qtas regras

# Mostrar 5 regras com maior suporte
inspect(regras[1:5])
# obs: LHS: left hand side; RHS: right hand side
summary(regras)


# Reoderdenar por confianca:
regras=sort(regras, by="confidence", decreasing=TRUE)
inspect(regras[1:5])

# Reoderdenar por lift:
regras=sort(regras, by="lift", decreasing=TRUE)
inspect(regras[1:5])

# buscar regras que involvam cerveja no lado direito (rhs):
regras=apriori(data=Groceries, 
               parameter=list(supp=0.001,
                              conf = 0.08), 
               appearance = 
                 list(default="lhs",
                      rhs="bottled beer"),
               control = list(verbose=F))
regras=sort(regras, by="lift", decreasing=TRUE)
inspect(regras[1:10])

# buscar regras que involvam cerveja no lado esquedo (lhs):
regras=apriori(data=Groceries, parameter=list(supp=0.001,conf = 0.15,minlen=2), 
               appearance = list(default="rhs",lhs="bottled beer"),
               control = list(verbose=F))

inspect(regras)

# Visualizacao
regras=apriori(Groceries, parameter = list(supp = 0.001, conf = 0.8))
plot(regras[1:20],method="graph",interactive=TRUE,shading=NA)