Data commit

Task/Pseudo-random-numbers-PCG32/Python/pseudo-random-numbers-pcg32-1.py

@@ -0,0 +1,47 @@
+mask64 = (1 << 64) - 1
+mask32 = (1 << 32) - 1
+CONST = 6364136223846793005
+
+
+class PCG32():
+
+    def __init__(self, seed_state=None, seed_sequence=None):
+        if all(type(x) == int for x in (seed_state, seed_sequence)):
+            self.seed(seed_state, seed_sequence)
+        else:
+            self.state = self.inc = 0
+
+    def seed(self, seed_state, seed_sequence):
+        self.state = 0
+        self.inc = ((seed_sequence << 1) | 1) & mask64
+        self.next_int()
+        self.state = (self.state + seed_state)
+        self.next_int()
+
+    def next_int(self):
+        "return random 32 bit unsigned int"
+        old = self.state
+        self.state = ((old * CONST) + self.inc) & mask64
+        xorshifted = (((old >> 18) ^ old) >> 27) & mask32
+        rot = (old >> 59) & mask32
+        answer = (xorshifted >> rot) | (xorshifted << ((-rot) & 31))
+        answer = answer &mask32
+
+        return answer
+
+    def  next_float(self):
+        "return random float between 0 and 1"
+        return self.next_int() / (1 << 32)
+
+
+if __name__ == '__main__':
+    random_gen = PCG32()
+    random_gen.seed(42, 54)
+    for i in range(5):
+        print(random_gen.next_int())
+
+    random_gen.seed(987654321, 1)
+    hist = {i:0 for i in range(5)}
+    for i in range(100_000):
+        hist[int(random_gen.next_float() *5)] += 1
+    print(hist)

Task/Pseudo-random-numbers-PCG32/Python/pseudo-random-numbers-pcg32-2.py

@@ -0,0 +1,33 @@
+def pcg32(seed_state=None, seed_sequence=None, as_int=True):
+    def next_int():
+        "return random 32 bit unsigned int"
+        nonlocal state, inc
+
+        state, xorshifted, rot = (((state * CONST) + inc) & mask64,
+                                  (((state >> 18) ^ state) >> 27) & mask32,
+                                  (state >> 59) & mask32)
+        answer = (((xorshifted >> rot) | (xorshifted << ((-rot) & 31)))
+                  & mask32)
+        return answer
+
+    # Seed
+    state = inc = 0
+    if all(type(x) == int for x in (seed_state, seed_sequence)):
+        inc = ((seed_sequence << 1) | 1) & mask64
+        next_int()
+        state += seed_state
+        next_int()
+
+    while True:
+        yield next_int() if as_int else next_int() / (1 << 32)
+
+
+if  __name__ == '__main__':
+    from itertools import islice
+
+    for i in islice(pcg32(42, 54), 5):
+        print(i)
+    hist = {i:0 for i in range(5)}
+    for i in islice(pcg32(987654321, 1, as_int=False), 100_000):
+        hist[int(i * 5)] += 1
+    print(hist)