preprocessMedMis.R

# Convert variable from factor into "Date" class
medMis$Effective.Date <- as.character(medMis$Effective.Date)
medMis$Effective.Date <- as.POSIXct(medMis$Effective.Date, format = "%m/%d/%Y")

# Order dataset by Effective.Date from 1990-2014
medMis <- (medMis[order(medMis$Effective.Date),])

# Create time-series data 
medMis_month <- as.data.frame(table(format(medMis$Effective.Date, "%Y-%m-01")), stringsAsFactors = FALSE)
medMis_plot <- as.data.frame(table(format(medMis$Effective.Date, "%Y-%m")), stringsAsFactors = FALSE)

# Change column name to "Time" and convert to date-time class
colnames(medMis_month)[1] <-"Time"   
medMis_month$Time <- as.POSIXct(medMis_month$Time)