improvements_Bagrat_Akopyan

checkHeight_script.R

@@ -18,32 +18,36 @@ students = transform(students, weight = as.numeric(as.character(weight)))
 
 students$name = c("Maria", "Franz", "Peter", "Lisa", "Hans", "Eva", "Mia", "Karl")
 
-
-
-checkHeight3 = function(students.input = students){
-
- result.frame = data.frame(matrix(NA, nrow = nrow(students.input), ncol = 2))
- colnames(result.frame) = c("name", "difference")
-
- male.mean = students.input %>%
- filter(sex == "M") %>%
- summarise(mean = mean(height))
- female.mean = students.input %>%
- filter(sex == "F") %>%
- summarise(mean = mean(height))
-
- for (i in 1:nrow(students.input)) {
- # calculate sex-specific deviations from the mean
- if (students.input[i, "sex"] == "F") {
- height.diff = 100*(students.input[i,]$height - female.mean$mean)
- }
- else {
- height.diff = 100*(students.input[i, ]$height - male.mean$mean)
- }
- result.frame[i, "name"] = as.character(students.input[i, "name"])
- result.frame[i, "difference"] = height.diff
- }
+# Input: 
+# Argument1, class of argument1 object
+
+#' calculate sex specific height difference of persons in a data.frame to 
+#' the average height
+#' @param students.input ('data.frame') \cr
+#' data.frame with columns height, sex and name 
+#' @return ('data.frame') \cr
+#' returns data.frame with names and difference to average gender height
+checkHeight3 <- function(students.input = students){
+ ## average height by gender
+ women_mean_height = mean(with(students.input, height[sex=="F"]))
+ men_mean_height = mean(with(students.input, height[sex=="M"]))
+
+ ## initialize vector to store height difference for every person in df
+ height_vector = c() 
+
+ ## apply function to calculate difference and store the value in height_vector
+ height_vector = apply(students.input, MARGIN = 1, 
+ FUN = function(student){
+ #substract the gender specific means from the individuals to get height differnces
+ (if (student["sex"] == "M") men_mean_height - as.numeric(student["height"]) 
+ else women_mean_height - as.numeric(student["height"]) ) 
+ } ) 
+
+ ## create return data.frame 
+ result.frame = data.frame("name" = students.input$name, "sexspec_height_diff" = height_vector*100)
+
+ ## return resulting data.frame
  return(result.frame)
 }
 
-checkHeight3(students.input = students)
+print(checkHeight3(students.input = students))