R Snippets

# Split into training and test sets
trainIndex <- createDataPartition(students$grade, p = 0.9,
                                  list = FALSE,
                                  times = 1)

studentsTrain <- students[ trainIndex,]
studentsTest  <- students[-trainIndex,]

# Create a proportion table
prop.table(table(loansTrain$default))

# Root Mean Squared Error (RMSE)
library(hydroGOF)
error <- rmse(results$prediction, results$actual)

# Filter out rows with non-numberical invalid ids
loans <- loans[grep("^\\d+$", loans$id),]

# Barplot of factors
barplot(table(ownedNotes$CREDIT_TREND))

# Rename column
library(plyr)
rename(d, c("beta"="two", "gamma"="three"))

# Find duplicated rows
vocabulary[duplicated(vocabulary$id),]

# Write CSV in R without row counts
write.csv(MyData, file = "MyData.csv",row.names=FALSE)

# Colors in a range
color_foo <- colorRampPalette(c("lightblue", "darkblue"))
colors <- color_foo(3)

# Prompt user for value and save as integer
readinteger <- function()
{ 
  val <- readline(prompt="Please, enter an integer: ")
  val <- as.integer(val)
}