height <- 170
weight <- 62

#身長を仮に，170cm
#体重を仮に，62kgと考える

(statistic <- weight/(height/100)^2)

#身長の単位を，cmからmに変えるために身長を100で割る

function( ){
statistic <- weight/(height/100)^2
}

function(weight, height){
statistic <- weight/(height/100)^2
}

function(weight, height){
statistic <- weight/(height/100)^2
return(statistic)
}

BMI <- function(weight, height){
statistic <- weight/(height/100)^2
return(statistic)
}

BMI(weight=62, height=170)
> [1] 21.45329

BMI <- function(weight, height){
statistic <- weight/(height/100)^2
if(statistic < 18.5){
message <- "やせ"
}
else if (statistic <25){
message <- "適正"
}
else if (statistic <30){
message <- "肥満（1度）"
}
else if (statistic <35){
message <- "肥満（2度）"
}
else if (statistic <40){
message <- "肥満（3度）"
}
else{
message <- "肥満（4度）"
}
return(statistic)
}

BMI <- function(weight, height){
statistic <- weight/(height/100)^2
if(statistic < 18.5){
message <- "やせ"
}
else if (statistic <25){
message <- "適正"
}
else if (statistic <30){
message <- "肥満（1度）"
}
else if (statistic <35){
message <- "肥満（2度）"
}
else if (statistic <40){
message <- "肥満（3度）"
}
else{
message <- "肥満（4度）"
}
result <- data.frame("BMI"=statistic, "判定"=message)
return(result)
}

BMI(weight=62, height=170)
> BMI 判定
> 1 21.45329 適正