Calculate Pi (π) using Leibniz formula
problem
It is pi day and you wish to write some code in your favorite language to calculate its value. You can pick Leibniz’s formula and implement it in Kotlin.
Recall the Leibniz formula:
SOLUTION
The series above can be implemented as follow (one solution):
fun calculatePi(): Double {
var index = 0
var pi = 0.0
var denominator = 1
val iterations = 1000000
while (index < iterations) {
if (index % 2 == 0)
pi += 4.0 / denominator
else
pi -= 4.0 / denominator
index += 1
denominator += 2
}
return pi;
}
Iterating the above 1M times will give the constant pi number.
running
fun main() {
println(calculatePi())
}
fun calculatePi(): Double {
var index = 0
var pi = 0.0
var denominator = 1
val iterations = 1000000
while (index < iterations) {
if (index % 2 == 0)
pi += 4.0 / denominator
else
pi -= 4.0 / denominator
index += 1
denominator += 2
}
return pi;
}
We can either copy & paste the code above into our Kotlin IDE or use the online Kotlin playground
COMPILE AND RUN
By using the terminal we can also compile it with kotlin compiler as follows:
kotlinc Pi.kt
the above will generate PiKt.class file that is to be executed as follows:
kotlin PiKt
output
3.1415916535897743
Looks correct!
conclusion
In this post we saw how to calculate the constant PI number by using a simple implementation of the Leibniz formula in Kotlin.
References:
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Ellion
Professional IT consultant, writer, programmer enthusiast interested in all sorts of coding.
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