source('../../Data/get_homicide_rates.R')
DF = get_homicide_rates()

r1 = range(DF$Number_Murder_Victims_Per_10K)
r2 = range(DF$Number_Firearm_Victims_Per_10K)
rs = c(r1, r2)

if( TRUE ){
    plot(DF$Year, DF$Number_Murder_Victims_Per_10K, ylim=c(min(rs), max(rs)), type='b', pch=19, col='blue', xlab='year', ylab='Number Per 10K')
    lines(DF$Year, DF$Number_Firearm_Victims_Per_10K, type='b', pch=19, col='green')
    grid()
    legend('topright', c('Murder', 'Firearm'), col=c('blue', 'green'), lty=1, pch=19)
}

m1 = lm(Number_Murder_Victims_Per_10K ~ Year, data=DF)
print(summary(m1))

## Create a new variable and study its behaviour over time: 
##
DF$Fraction_of_Firearm_Murders = DF$Number_Firearm_Victims/DF$Number_Murder_Victims

if( TRUE ){
    plot(DF$Year, DF$Fraction_of_Firearm_Murders, type='b', pch=19, col='blue', xlab='year', ylab='Fraction of Firearm Murders')
    grid()
}