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import scala.math._

/*  cacluate pi

Pi = 4*(1 - 1/3 + 1/5 -1/7+....)
write a function that calculates pi to an accuracy of 5 decimal places
*/
// 1/(2*x+1)*4<1e-6
//4*1e6<2*x+1
// x>(4*1e6-1)/2
// x>2*1e6

def npi(n: Int) = pow(-1,n)/(2*n+1)

val N: Int = 2e6.toInt ;

val pi = (0 to N).map(npi).sum*4

println(pi)

// calculate the area of a circle
def circleArea(r:Double) = pi*r*r

val a = 3
println(circleArea(3))

// vim: set ts=4 sw=4 et: