1+1 2*3 9/2 x<-2 y<-3 z<-x+y w<-c(4,6,8) w w/x #建立身高、體重資料物件 height <-1.77 weight <-72 #建立BMI公式，並命名為bmi bmi<-weight/height^2 bmi <- round(bmi,2)#取小數點到第二位 bmi_j<-bmi>18.5 & bmi<24#判斷bmi是否在正常範圍 bmi_j ##向量(vector)運算 weight_g <- c(70, 62, 85, 60, 75) height_g <- c(1.7, 1.68, 1.82, 1.62, 1.75) bmi_g<-weight_g/height_g^2 bmi_g bmi_g <- round(bmi_g,2) bmi_g_j<-bmi_g>18.5 & bmi_g<24 bmi_g_j bmi_g_j <- 請輸入(bmi_g_j)#用平均數計算bmi合格率(邏輯值也可以運算。FALSE=0, TRUE=1) bmi_g_j #為向量命名 names(weight_g)<-c("A","B","C","D","E") weight_g #選擇vector內元素 weight_g[3] weight_g[1:3] weight_g[weight_g>70] #數學運算 length(weight_g)#計算向量內的元數個數 mean(weight_g) max(weight_g) which.max(weight_g) sum(weight_g) min(weight_g) sort(weight_g)#排序(預設是由小到大) sort(weight_g, decreasing = TRUE)#由大到小 #將身高換算為英吋(1 inch = 2.54 cm)，取小數點後一位 height_g round(height_g*100/2.54,1) ##畫長條圖 barplot(weight_g, col = c("skyblue", "magenta", "oldlace", "azure", "tomato4")) colors()#查詢R的內建顏色 barplot(weight_g, col = c(6:10))#用內建預設的第6種到第10種顏色 BMI <- function(height, weight){ bmi <- weight/(height^2) return(bmi) } BMI_J <- function(height, weight){ bmi <- weight/(height^2) bmi_j <- bmi>18.5 & bmi<24 return(bmi_j) }