高校数学の質問スレ（医者・東大卒専用） Part438

set.seed(2025)
str="
FLU
Log-Normal Distribution for Influenza
typical Parameters (based on research):
𝜇: ~0.5–1.0 (log-mean)
𝜎: ~0.3–0.5 (log-standard deviation)
Gamma Distribution for Influenza
typical Parameters (based on research):
Shape (𝑘): ~2.0–3.0
Scale (𝜃): ~0.5 days
"
par(bty='l')
calc=function(){
m=runif(1,0.5,1.0)
s=runif(1,0.3,0.5)
fl=function(x) dlnorm(x,m,s)

fdl=function(y) integrate(function(x) fl(x+y)*fl(y),0,Inf)$value
fdl=Vectorize(fdl)
# curve(fdl(x),0,5)
integrate(fdl,1,2)$value
}
p=replicate(1e3,calc())
hist(p)