Implementation of Trapezoidal Rule (Integral Approximation) written in R.
Enter beginning of interval: -2 Enter end of interval: 2 Enter number of iterations: 1000000 Integral is equal to: 5.33336533334409
# ? 2018 TheFlyingKeyboard and released under MIT License # theflyingkeyboard.net f <- function(x) { return(x * x) } intervalBegin <- as.double(readline(prompt = "Enter beginning of interval: ")) intervalEnd <- as.double(readline(prompt = "Enter end of interval: ")) iterations <- as.integer(readline(prompt = "Enter number of iterations: ")) step = (intervalEnd - intervalBegin) / iterations integral = 0.5 * (f(intervalBegin) + f(intervalEnd)) for(i in 0:iterations){ integral = integral + f(intervalBegin + step * i) } integral = integral * step print(paste("Integral is equal to: ", integral))
R Trapezoidal Rule