Comment the recursion exercise

lab_loops.Rmd

@@ -92,7 +92,8 @@ while (x < 100000) {
 head(while.sum)
 ```
 
-3. Create a data frame with two numeric and one character vector. Write a loop that loops over the columns and reports the sum of the column values if it is numeric and the total number of characters if it is a character vector.
+3. Create a data frame with two numeric and one character vector. Write a loop that loops over the columns and reports the sum of the column values if it is numeric and the total number of characters if it is a character vector.  
+**Tips** to count number of characters, you can use `nchar` function.  
 
 ```{r,accordion=TRUE}
 vector1 <- 1:10
@@ -114,22 +115,23 @@ sum.vec
 
 ```{r,accordion=TRUE}
 dfr.info <- function(dfr) {
-sum.vec <- vector()
-for (i in 1:ncol(dfr)) {
-	if (is.numeric(dfr[,i])) {
-		sum.vec[i] <- mean(dfr[,i])
-	} else {
-		sum.vec[i] <- sum(nchar(dfr[,i]))
-	}
-}
-sum.vec
+  sum.vec <- vector()
+  for (i in 1:ncol(dfr)) {
+  	if (is.numeric(dfr[,i])) {
+  		sum.vec[i] <- mean(dfr[,i])
+  	} else {
+  		sum.vec[i] <- sum(nchar(dfr[,i]))
+  	}
+  }
+  sum.vec
 }
 ```
 
 5.  Read up on the if-else function in R. If possible use the if-else function to answer question 3.
 
 6.  In all loops that we tried out we have created the variable where the output is saved outside the loop. Why is this?
 
+<!--
 7. <i class="fas fa-exclamation-circle"></i> **Advanced:** At the lecture an approach to calculate factorials were implemented using recursion (function calling itself). Here we instead will have a go at generating Fibonacci numbers. A fibonacci number is part of a series of number with the following properties:
 
 The first two numbers in the Fibonacci sequence are either 1 and 1, or 0 and 1, depending on the chosen starting point of the sequence, and each subsequent number is the sum of the previous two. Hence:
@@ -141,3 +143,4 @@ or
 `1, 1, 2, 3, 5, 8, 13, 21, ...`
 
 Try to generate such a series using a recursive approach.
+-->