Add a fast std_rand implementation + other enhancements

p2.gp

@@ -1,5 +0,0 @@
-#!/usr/bin/gnuplot -p
-splot \
- "/tmp/rnd3d.dat" using 1:2:3 w l lt rgb "green" t "std-rand" \
-,"/tmp/rnd3d.dat" using 1:2:4 w l lt rgb "blue" t "mod-rand" \
-,"/tmp/rnd3d.dat" using 1:2:5 w l lt rgb "red" t "prop-rand"

runplot3d.sh

@@ -10,6 +10,12 @@ then
     exit 1
 fi
 
+if [ "$1" = "-h" ]
+then
+    usage
+    exit 0
+fi
+
 maxres=${1:-100}
 minres=${2:-90}
 iter_res=${3:-10000}

sadrand.py

@@ -2,14 +2,11 @@
 
 import random
 import argparse
+import math
 import sys
 import warnings
 
-try:
-    from tqdm import tqdm
-except (NameError, ImportError):
-    warnings.warn("tqdm module not found, no progress bar")
-    tqdm = lambda it, **kwargs: iter(it)
+tqdm = lambda it, **kwargs: iter(it)
 
 def std_rand(args):
     result = [0 for _ in range(args.resolution)];
@@ -17,6 +14,17 @@ def std_rand(args):
         result[random.randint(0, args.resolution-1)] += 1
     return result
 
+def std_rand_fast(args):
+    result = [0 for _ in range(args.resolution)];
+    nbits = math.ceil(math.log2(args.resolution))
+    for _ in tqdm(range(args.iter), unit_scale=True, total=args.iter):
+        while True:
+            rnd = random.getrandbits(nbits)
+            if rnd < args.resolution:
+                break
+        result[rnd] += 1
+    return result
+
 def rnd_bytes(count, chunk_size=4096):
     to_read = count
     with open('/dev/urandom', 'br') as rfd:
@@ -36,27 +44,39 @@ def generic_rand(args, rnd_fun):
 mod_rand = lambda args: generic_rand(args,
                                  lambda rbyte: rbyte % args.resolution)
 prop_rand = lambda args: generic_rand(args,
-                                  lambda rbyte: (rbyte * (args.resolution)) // 256)
-
-parser = argparse.ArgumentParser();
-parser.add_argument('-i', '--iter', type=lambda v: int(v,0), default=0x100000);
-parser.add_argument('-r', '--resolution', type=lambda v: int(v,0), default=100);
-parser.add_argument('-c', '--chunk-size', type=int, default=4096);
-parser.add_argument('-R', '--relative', action="store_true", default=False)
+                                  lambda rbyte:(rbyte*(args.resolution)) // 256)
 
-args = parser.parse_args();
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser();
+    parser.add_argument('-i', '--iter', type=lambda v: int(v,0),
+                        default=0x100000);
+    parser.add_argument('-r', '--resolution', type=lambda v: int(v,0),
+                        default=100);
+    parser.add_argument('-c', '--chunk-size', type=int, default=4096);
+    parser.add_argument('-R', '--relative', action="store_true",
+                        default=False);
+    parser.add_argument('-p', '--progress', action="store_true",
+                        default=False);
+    parser.add_argument('--std', action="store_true", default=False,
+                        help="Use random.randint instead of random.getrandbits")
 
+    args = parser.parse_args();
 
-methods = (std_rand, mod_rand, prop_rand)
-results = [method(args) for method in methods]
+    if args.progress:
+        try:
+            from tqdm import tqdm
+        except (NameError, ImportError):
+            warnings.warn("tqdm module not found, no progress bar")
 
-if args.relative:
-    for i, result in enumerate(results):
-        results[i] = [(r / args.iter) * args.resolution for r in result]
-    
+    methods = (std_rand if args.std else std_rand_fast, mod_rand, prop_rand)
+    results = [method(args) for method in methods]
 
-for i, res in enumerate(zip(*results)):
     if args.relative:
-        i = i / args.resolution
-    sys.stdout.write(str(i) + ' ' + (' '.join([str(r) for r in res]))+'\n')
+        for i, result in enumerate(results):
+            results[i] = [(r / args.iter) * args.resolution for r in result]
+
+    for i, res in enumerate(zip(*results)):
+        if args.relative:
+            i = i / args.resolution
+        sys.stdout.write(str(i) + ' ' + (' '.join([str(r) for r in res]))+'\n')