Do you know where your variables are? PerlMonks

### Re^3: Send x% of the users to A, the rest to B

by BrowserUk (Pope)
 on Oct 27, 2012 at 21:02 UTC ( #1001232=note: print w/replies, xml ) Need Help??

Interesting to see that ... it takes a few dozen iterations to actually reach middle ground:

That is the nature of randomness. If it was exactly 50:50, it wouldn't be random.

But the more trials you run, the closer it will tend. This is more evident if you run this version with various different resets:

```C:\test>perl
-E"{++\$t;\$r=`perl -E\"say rand()\"`;\$r<.5?++\$a:++\$b; printf qq[\r%.3f
+: %.3f], \$a*100/\$t, \$b*100/\$t; \$t>\$ARGV[0] and say and \$t=\$a=\$b=0; re
+do}" 10
45.455 : 54.545
27.273 : 72.727
36.364 : 63.636
54.545 : 45.455
72.727 : 27.273
63.636 : 36.364
36.364 : 63.636
45.455 : 54.545
27.273 : 72.727
36.364 : 63.636
72.727 : 27.273
45.455 : 54.545
54.545 : 45.455
63.636 : 36.364

C:\test>perl
-E"{++\$t;\$r=`perl -E\"say rand()\"`;\$r<.5?++\$a:++\$b; printf qq[\r%.3f
+: %.3f], \$a*100/\$t, \$b*100/\$t; \$t>\$ARGV[0] and say and \$t=\$a=\$b=0; re
+do}" 100
52.475 : 47.525
52.475 : 47.525
52.475 : 47.525
46.535 : 53.465
45.545 : 54.455
51.485 : 48.515
41.584 : 58.416
46.535 : 53.465
42.574 : 57.426
40.594 : 59.406

C:\test>perl
-E"{++\$t;\$r=`perl -E\"say rand()\"`;\$r<.5?++\$a:++\$b; printf qq[\r%.3f
+: %.3f], \$a*100/\$t, \$b*100/\$t; \$t>\$ARGV[0] and say and \$t=\$a=\$b=0; re
+do}" 1000
49.750 : 50.250
51.349 : 48.651
48.651 : 51.349
53.047 : 46.953

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