Logarithmic code in R programming with 3 variables

Question

I have written a small program to develop logarithmic code and I have taken 3 variables, x, y and p, where x is base, y is log value and p is default value (power of 'x'). Now I am not getting error when I executed it but it didn't display any answer on terminal. It will be handy when someone provide solution to it.

algo1 <- function(x, y) {
  p <- 1
if (x ^ p == y) {
  print(p)
} else {
  p <- p + 1
}

algo1(3, 81)

Answer 1

There are a few issues I can see here.

1. Assigning p inside the function, while it seems the function has to be recursive.

2. OR, considering for some reason you want to increment p within the else condition and still not do anything with the incremented value, not returning anything here.

If I may, I would change the function to something like:

algo1 <- function(x,y,p = 1) {
  if (x ^ p == y) {
    print(p)
  } else {
    p = p + 1
    algo1(x,y,p)
  }
}

which returns the value of p for which x^p ==y

> algo1(3,81)
[1] 4

OR, you can also use:

round(y ^ (1.0/x))

p.s. maybe include a check and exit conditions for x^p > y?