Data commit

Task/Percolation-Mean-cluster-density/Wren/percolation-mean-cluster-density.wren

@@ -0,0 +1,82 @@
+import "random" for Random
+import "/fmt" for Fmt
+
+var rand = Random.new()
+var RAND_MAX = 32767
+
+var list = []
+var w = 0
+var ww = 0
+
+var ALPHA = "+.ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+var ALEN  = ALPHA.count - 3
+
+var makeList = Fn.new { |p|
+    var thresh = (p * RAND_MAX).truncate
+    ww = w * w
+    var i = ww
+    list = List.filled(i, 0)
+    while (i != 0) {
+        i = i - 1
+        var r = rand.int(RAND_MAX+1)
+        if (r < thresh) list[i] = -1
+    }
+}
+
+var showCluster = Fn.new {
+    var k = 0
+    for (i in 0...w) {
+        for (j in 0...w) {
+            var s = list[k]
+            k = k + 1
+            var c = (s < ALEN) ? ALPHA[1 + s] : "?"
+            System.write(" %(c)")
+        }
+        System.print()
+    }
+}
+
+var recur // recursive
+recur = Fn.new { |x, v|
+    if (x >= 0 && x < ww && list[x] == -1) {
+        list[x] = v
+        recur.call(x - w, v)
+        recur.call(x - 1, v)
+        recur.call(x + 1, v)
+        recur.call(x + w, v)
+    }
+}
+
+var countClusters = Fn.new {
+    var cls = 0
+    for (i in 0...ww) {
+        if (list[i] == -1) {
+            cls = cls + 1
+            recur.call(i, cls)
+        }
+    }
+    return cls
+}
+
+var tests = Fn.new { |n, p|
+    var k = 0
+    for (i in 0...n) {
+        makeList.call(p)
+        k = k + countClusters.call() / ww
+    }
+    return k / n
+}
+
+w = 15
+makeList.call(0.5)
+var cls = countClusters.call()
+System.print("width = 15, p = 0.5, %(cls) clusters:")
+showCluster.call()
+
+System.print("\np = 0.5, iter = 5:")
+w = 1 << 2
+while (w <= (1 << 13)) {
+    var t = tests.call(5, 0.5)
+    Fmt.print("$5d $9.6f", w, t)
+    w = w << 1
+}