# Map 1-based optional input ports to variables
dataset1 <- maml.mapInputPort(1) # class: data.frame

# Sample operation
dataset1$AgeGroup <- ifelse(dataset1$Age < 16, "Young", ifelse(dataset1$Age > 60, "Old", "Middle"))

# Select data.frame to be sent to the output Dataset port
maml.mapOutputPort("dataset1");