Pseudo-random numbers/Combined recursive generator MRG32k3a: Difference between revisions
Pseudo-random numbers/Combined recursive generator MRG32k3a (view source)
Revision as of 00:09, 25 April 2021
, 3 years ago→{{header|Perl}}
Line 589:
1: 20002 2: 20060 3: 19948 4: 20059 5: 19931
</pre>
=={{header|Kotlin}}==
{{trans|C++}}
<lang scala>import kotlin.math.floor
fun mod(x: Long, y: Long): Long {
val m = x % y
return if (m < 0) {
if (y < 0) {
m - y
} else {
m + y
}
} else m
}
class RNG {
// first generator
private val a1 = arrayOf(0L, 1403580L, -810728L)
private val m1 = (1L shl 32) - 209
private var x1 = arrayOf(0L, 0L, 0L)
// second generator
private val a2 = arrayOf(527612L, 0L, -1370589L)
private val m2 = (1L shl 32) - 22853
private var x2 = arrayOf(0L, 0L, 0L)
private val d = m1 + 1
fun seed(state: Long) {
x1 = arrayOf(state, 0, 0)
x2 = arrayOf(state, 0, 0)
}
fun nextInt(): Long {
val x1i = mod(a1[0] * x1[0] + a1[1] * x1[1] + a1[2] * x1[2], m1)
val x2i = mod(a2[0] * x2[0] + a2[1] * x2[1] + a2[2] * x2[2], m2)
val z = mod(x1i - x2i, m1)
// keep last three values of the first generator
x1 = arrayOf(x1i, x1[0], x1[1])
// keep last three values of the second generator
x2 = arrayOf(x2i, x2[0], x2[1])
return z + 1
}
fun nextFloat(): Double {
return nextInt().toDouble() / d
}
}
fun main() {
val rng = RNG()
rng.seed(1234567)
println(rng.nextInt())
println(rng.nextInt())
println(rng.nextInt())
println(rng.nextInt())
println(rng.nextInt())
println()
val counts = IntArray(5)
rng.seed(987654321)
for (i in 0 until 100_000) {
val v = floor((rng.nextFloat() * 5.0)).toInt()
counts[v]++
}
for (iv in counts.withIndex()) {
println("${iv.index}: ${iv.value}")
}
}</lang>
{{out}}
<pre>1459213977
2827710106
4245671317
3877608661
2595287583
0: 20002
1: 20060
2: 19948
3: 20059
4: 19931</pre>
=={{header|Perl}}==
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