Question

7. #4. 18 Following is a recursive function which takes as input (argument) a vector $x$ and returns a scalar. Either by looking carefully at the function, or by running the function with a few simple input vectors and observing the returned values in each case, determine what the function is doing. 29 00- "**{r} 01 - myfun=function(x){ 02 - if(length(x)=-1){return(x) C03 - } else 84 return(x[1]+my funcx[-1])) 205 - ) 206 myfun(c(1:1000)) #here's what happens when it is applied to 1:1000 207 208 209 ANSWER (4 points) (Describe in precise words what the function does) 210 211 212 Modify the function slightly so that it returns the value: 213 214 S\sum_{i=1}^n e^{x_i}$ 215 216 In other words, we want to write a function that calculates the sum of the exponential of each component of the input vector $xs. 217 Test your function with the argument vector: X=C(2,1,3,0.4). 219 You should get an answer approximately equal to 31.6847 220 221 ANSWER (6 points): 222 - 223 # add your own R code below this line 224 225 226 218 I

Answer 1

c(1:1000) means, a vector of [1,2,3,...1000].

The given function describing the sum all elements in the given vector.

• 1+ [2,3,4,....1000]
• 3 + [3,4,5,.....1000]
• 6 + [4,5,6,....1000]
• ....

The answer is 500500 i.e the sum of [1,2,3.....1000]

The Modified code for calculating sum of exponential values of given vector

newfunction = function(x){
res = 0
for (val in x){
res = res + exp(val)
}
return(res)
}
newfunction(c(2,1,3,0,4))

Answer is 85.79102