# MySquare Example
# Collect execution times for a user defined function
# slowSquare.  Then plot the results.

slowSquare <- function(v) {
   result <- NULL
   for(i in 1:length(v)) {
      result[i] <- v[i]^2 
   }
   return(result)
}

cat("Compute squares of 1:100 with slowSquare.\n")
print(slowSquare(1:100))

cat("Compute time to compute squares of 1:10000")
cat(" with slowSquare.\n")

# Collect times to compute squares for arrays
# of various sizes.
lengths = NULL
times = NULL
for(n in seq(1000, 10000, 1000)) {
   cat("n = ", n, "\n")
   lengths = c(lengths, n)
   times = c(times, as.numeric(system.time(slowSquare(1:n))["elapsed"]))
}

# Print lengths and times
cat("Array Lengths\n")
print(lengths)
cat("Execution Times\n")
print(times)

# Plot times vs. lengths
plot(lengths, times)