setwd("C:/FileSystem/Google Drive/GonzagaMathFiles/math422_sp20/datasets")
library(readxl)
d <- read_excel("covid_by_state_apr6.xlsx")
head(d)
class(d)
plot(d$pop_2020est,d$total_covid_tests)
plot(d$pop_2020est,d$total_covid_tests,log="xy")
x=d$pop_2020est
y=d$total_covid_tests
plot(x,y,log="xy")
x=d$pop_2020est
y=d$total_covid_tests
plot(x,y,log="xy",xlab="state pop",ylab="covid tests")
x=d$pop_2020est
y=d$total_covid_tests
plot(log(x),log(y),xlab="state pop",ylab="covid tests")
x=d$pop_2020est
y=d$total_covid_tests
plot(log(x),log(y),xlab="log(state pop)",ylab="log(covid tests)")
x=d$pop_2020est
y=d$total_covid_tests
plot(x,y,log="xy",xlab="state pop",ylab="covid tests")
x=d$pop_2020est
y=d$total_covid_tests
plot(x,y,log="",xlab="state pop",ylab="covid tests")
x=d$pop_2020est
y=d$total_covid_tests
plot(x,y,log="xy",xlab="state pop",ylab="covid tests")
x=log(d$pop_2020est)
y=log(d$total_covid_tests)
plot(x,y)
lm(y~x)
b = cov(x,y)/var(x)
a = mean(y)-b*mean(x)
linefit = a+b*x
SSE = sum((y-linefit)^2)
MSE = SSE/(n-2)
n=length(x)
b = cov(x,y)/var(x)
a = mean(y)-b*mean(x)
linefit = a+b*x
SSE = sum((y-linefit)^2)
MSE = SSE/(n-2)
a
b
lr = lm(y~x)
lr
abline(lr)
lr$coefficients
lr$fitted.values
sum((lr$fitted.values-y)^2)
sum((lr$fitted.values-y)^2)
SSE
x
y
cor(x,y)
cov(x,y)/sd(x)/sd(y)
cor.test(x,y)
alpha=0.05
b+c(-1,1)*qt(1-alpha/2,length(x)-2)*sqrt(MSE/(length(x)-1)/var(x))
b = cov(x,y)/var(x)
a = mean(y)-b*mean(x)
linefit = a+b*x
SSE = sum((y-linefit)^2)
MSE = SSE/(n-2)
alpha=0.05
b+c(-1,1)*qt(1-alpha/2,length(x)-2)*sqrt(MSE/(length(x)-1)/var(x))
b
lr
confint(lr)
line(x,-5.3180617+0.7178952*x,col="red")
lines(x,-5.3180617+0.7178952*x,col="red")
lines(x,-0.9132671+0.7178952*x,col="red")
lines(x,-0.9132671+1.0068494*x,col="red")
lines(x,-5.3180617+1.0068494*x,col="green")
plo(x,y)
plot(x,y)
cor.test(x,y)
xval=18
a+b*xval
a+b*xval+c(-1,1)*qt(1-alpha/2,n-2)*sqrt(MSE*(1+1/n+(xval-mean(x))^2/(n-1)/var(x)))
d
plot(d[2:7])
plot(d[2:7],log="xy")
d$tot_covid_deaths
log(d$tot_covid_deaths)
?log1p
log1p(d$tot_covid_deaths)
cor.test(log(d$total_covid_tests),log(d$tot_covid_deaths))
cor.test(log(d$total_covid_tests),log1p(d$tot_covid_deaths))
cor.test(log1p(d$total_covid_tests),log1p(d$tot_covid_deaths))