Re^2: A script with a loop is running my computer Out of memory

The assumption is that into each generation is born a certain number of children, and those children have a certain number of children, etc. Gender is not being taken into account, and the children's spouses are not being tallied here. And no, this is not a worm population growth chart. I am just trying to get an idea of how many generations it would take to get to about 250 billion people born into it, give or take a couple billion. I haven't taken interbreeding into account either, as after about a 5 generation gap some consider it safe to interbreed though some consider sooner than that safe. Doing that however would add yet even more complexity that I haven't even tried to think about adding.

Have a cookie and a very nice day!

Lady Aleena

Comment on Re^2: A script with a loop is running my computer Out of memory

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Re^3: A script with a loop is running my computer Out of memory by jdporter (Paladin) on Feb 03, 2011 at 15:48 UTC
Look, if you know the generational growth rate (i.e. for each person in generation N, there are 2.5 people in generation N+1, or whatever), then just start with your 250 billion and work backwards. (2.5 is the average of `rand(6)`.) `$n = 250_000_000_000; $a = 2.5; while ($n>2) { print "$n\n"; $n /= $a; } ^D 250000000000 100000000000 40000000000 16000000000 6400000000 2560000000 1024000000 409600000 163840000 65536000 26214400 10485760 4194304 1677721.6 671088.64 268435.456 107374.1824 42949.67296 17179.869184 6871.9476736 2748.77906944 1099.511627776 439.8046511104 175.92186044416 70.368744177664 28.1474976710656 11.2589990684262 4.5035996273705` [download] There. 28 generations. Approximately.	[reply] [d/l] [select]
Re^4: A script with a loop is running my computer Out of memory by GrandFather (Saint) on Feb 03, 2011 at 19:49 UTC
Or by modifying the compound interest formula to kill off the previous generation: `use strict; use warnings; my $startPop = 4; my $targetPop = 250e9; my $increase = 2.5; my $n = int ((log($targetPop) - log($startPop)) / log($increase) + 0.5 +); my $pop = int ($startPop * ($increase) ** $n); print "$pop population after $n generations\n";` [download] Prints: `222044604925 population after 27 generations` [download] Add 1 instead of 0.5 in the $n calculation if you want a minimum of $targetPop. True laziness is hard work	[reply] [d/l] [select]