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Liam Guest

Posted: Fri Jan 27, 2006 16:01 Post subject: 


The formula is right, I tried it. 

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Locutus Guest

Posted: Fri Apr 18, 2008 11:01 Post subject: 


Here are the formulas, stated somewhat more clearly:
P := current population
G := expected population growth
D := planet diameter
R := racial bonus (from 0.6 to 1.6)
T := tax rate (from 0 to 0.15)
L := leisure park  1 if leisure park is built, 0 otherwise
G = 0.1 * ( 30D  P ) * R * ( 0.1 + 0.03*L  T )
Mathy people will notice that P(t) is just an exponential function, asymptotically approaching the maximum size. However, due to roundoff error, it will probably never actually reach the maximum size
Edit: corrected formula
Last edited by Locutus on Sun Apr 20, 2008 08:58; edited 1 time in total 

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Aurion Member of the House
Joined: 31 Jan 2004 Posts: 591 Location: Alpha Section

Posted: Fri Apr 18, 2008 14:21 Post subject: 


Why did you revive this thread, after two long years?
Btw, it is one of the oldest threads here, look at the post date of the initial post.
And the part with never reaching the calculated maximum is true, but it gets really close, so you will not miss it that much. _________________ Member of the House Aurion in the house Ashera 

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Locutus Guest

Posted: Sat Apr 19, 2008 11:16 Post subject: 


I revived it because I needed to check some of the formulas for a program that I'm writing... I made the post because I thought that the formulas were very vague about the bounds of the variables (whether to use 1.6 or 160 for the racial bonus, for example.) 

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alphabravo Major
Joined: 15 Feb 2004 Posts: 827 Location: UK

Posted: Sat Apr 19, 2008 17:19 Post subject: 


it varies from 60% to 160%, which, in a numerical form, is 0.6 to 1.6 _________________ Major alphabravo in the house Ashera 

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Locutus Guest

Posted: Sat Apr 19, 2008 22:51 Post subject: 


Also, the original post did not make very clear how exactly tax was incorporated into the formula:
Quote:  growth factor = race factor / 100 (for 0% tax, each percent tax reduces the growth by 10%, a leisure park increases by 30%) 
versus:
Quote:  G = 0.01 * ( 30D  P ) * R * ( 0.1 + 0.03*L  T ) 
Some may think my revival of this thread is unnecessary, but I think my formula is somewhat more clear than the other one. Either way, it doesn't hurt anything. 

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Aurion Member of the House
Joined: 31 Jan 2004 Posts: 591 Location: Alpha Section

Posted: Sun Apr 20, 2008 05:49 Post subject: 


Hey, no offense meant. Just wondering that you chose an two year old thread.
If i would deem your post not appropriate, i would have told you right away.
It is good that some players tend to make their knowlegde available for the public. _________________ Member of the House Aurion in the house Ashera 

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BlackSkull Guest

Posted: Sun Apr 20, 2008 08:28 Post subject: 


Locutus wrote:  Also, the original post did not make very clear how exactly tax was incorporated into the formula:
Quote:  growth factor = race factor / 100 (for 0% tax, each percent tax reduces the growth by 10%, a leisure park increases by 30%) 
versus:
Quote:  G = 0.01 * ( 30D  P ) * R * ( 0.1 + 0.03*L  T ) 
Some may think my revival of this thread is unnecessary, but I think my formula is somewhat more clear than the other one. Either way, it doesn't hurt anything. 
This formula is still wrong.
My Testplanet have a Diameter of 49586 km, with a Population of 1486652 Insectoids (R= 1.4). The Planet have a leisurepark.
G = 0.01 * (30*49589  1486652) * 1.4 * (0.1 + 0.03  0.15)
G = 0.01 * (1018) * 1.4 * (0.02)
G = 10.18 * 1.4 * 0.02
G = 0.28504 ~ 0 (round and cut set the return to 0)
BUT : The G in real was 2 and not 0.
Second Testplanet :
45767 km Diameter, 1372727 Morphoids (1.6), 14 % tax, Leisure Park
0 Grow
G = 0.01 * (30*45767  1372727) * 1.6 * (0.1 + 0.03  0.14)
G = 0.01 * (283) * 1.6 * (0.1)
G = 0.4528 ~ 0
The Real G was 0 too.
Its a riddle 

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Locutus Guest

Posted: Sun Apr 20, 2008 09:04 Post subject: 


BlackSkull wrote: 
My Testplanet have a Diameter of 49586 km, with a Population of 1486652 Insectoids (R= 1.4). The Planet have a leisurepark.
G = 0.01 * (30*49589  1486652) * 1.4 * (0.1 + 0.03  0.15)
G = 0.01 * (1018) * 1.4 * (0.02)
G = 10.18 * 1.4 * 0.02
G = 0.28504 ~ 0 (round and cut set the return to 0)
BUT : The G in real was 2 and not 0.
Second Testplanet :
45767 km Diameter, 1372727 Morphoids (1.6), 14 % tax, Leisure Park
0 Grow
G = 0.01 * (30*45767  1372727) * 1.6 * (0.1 + 0.03  0.14)
G = 0.01 * (283) * 1.6 * (0.1)
G = 0.4528 ~ 0
The Real G was 0 too.
Its a riddle 
It turns out that both of us made errors  my formula was wrong, but it should be correct now. I had swapped a 0.1 instead of 0.01 at the beginning.
On your first planet, this should give you 2.6 which should round down to 3, but somehow does not. Check with http://www.kosmor.de/download/wachstum.swf
Also, on your first planet, you used 49589 for planet size instead of 49586. Either way, you are expected to have 3 growth, but somehow you only got 2.
On your second planet, you used the now correct formula instead of the one I had originally posted, which is why it worked correctly.
As for the 2/3 error on the first planet, I have noticed slight rounding errors on some of my planets  for example:
Size: 37708 km
Population: 1078293
Tax: 9%
Race: 1.6 (morphoid)
Leisure park: yes
G = 0.1 * (30*37708  1078293) * 1.6 * (0.1 + 0.03  0.09)
G = 338.9 > 339
http://www.kosmor.de/download/wachstum.swf agrees with my formula, but in Kosmor, I had 340 growth. 

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alphabravo Major
Joined: 15 Feb 2004 Posts: 827 Location: UK

Posted: Sat Apr 18, 2009 06:45 Post subject: 


I'm almost certain that only the integer parts of growth or negative growth are taken.
Therefore
12.1 => 12
12.8 => 12
2.1 => 2
2.8 => 2 _________________ Major alphabravo in the house Ashera 

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