ZERO trade

[SlowThinker]

Originally posted by La Fayette If you truncate civ 2.99, guess what you get.

La Fayette,
do you want to say that the Civ 2 was Civ 2.99 in fact and so there will not be a difference between both versions?
BTW, did you read my message (MP)?
Edit: I mean the PM about the multiplayer.

[shade]

Now there still is the question how the modifiers work.
eg modifiers m1,m2,m3
trade in city T1,T2

is it:
((((T1+T2+4)/8)xm1)xm2)xm3

or is it

((T1+T2+4)/8)+((T1+T2+4)/8)xm1+((T1+T2+4)/8)xm2+((T1+T2+4)/8)xm3

?????
(probably the second one I guess)

Shade

[La Fayette]

Originally posted by shade

?????
(probably the second one I guess)
Shade

If you wish to make friends with Slow Thinker, you should never guess, you should test .
Contrary to what you guess, the multipliers I have tested (namely 'both cities yours','road' and 'railroad') follow your formula #1.

(La Fayette, ready to dream about SlowThinker after that little bit of testing)

[La Fayette]

civ 2.99

ST
I meant that civ2 was such fun that it might just as well be civ3 or 4 or more than that (but I strongly hope that civ3 will be even more fun than civ2).
I got your message and replied. Let me know if there was a problem with my reply.

[shade]

Originally posted by La Fayette
If you wish to make friends with Slow Thinker, you should never guess, you should test .
Contrary to what you guess, the multipliers I have tested (namely 'both cities yours','road' and 'railroad') follow your formula #1.

I'll do some testing in the morning but I am sure it will be Nr 2,when I guess I have my reasons
->easier to program
->easier math for the programmer
->les problems with values dissipathing

(little sidenote : ppl have always been complaning about the food model=> did some calculationson them lately=> SID ACTUALLY USED A REALLIFE POPULATIONGROWTHALGORITHM(ie: dN=aN(1-N/K) ) =>9.9/10 for realism)

Shade

[SlowThinker]

La Fayette,
the last PM obtained from you is 28-10-2001. Then I posted you a PM on 29-10 and then a copy tomorrow.
If you don't have them you can read
A game for rookies (for SP players).

Originally posted by shade
SID ACTUALLY USED A REALLIFE POPULATIONGROWTHALGORITHM(ie: dN=aN(1-N/K) ) =>9.9/10 for realism

Can you explain?
BTW, did you see this: http://www.steffengerlach.de/cz/

[shade]

Can you explain?

Ok here we go:
The most simpel population model you can imagine is one where growth is linear equivalent with the population(dN=growth of population,N=population,a=the constant)
then this would give you this formula
dN=a*N
when we differentiate this we get an exponential growth
N=e^(a*t)
When we now add a restriction=>"there is only a limited amount of food that can be produced",we get a new (constant)Variable K wich represents the "support power"(don't know a better translation) of your food.The new formula will look like this:
dN=a*N*(1-N/K).
(this shows that if you heve a bigger population then you can support N/K>1 and dN becomes negative ie. you have ppl starving.When your population N When you now plot a curve that shows how your population grows over time you get something that looks like a tangent put on his side.
When you plot out the population growth in Civ2 vs the number of turns it takes you get a curve that looks exactly the same,and you'll recognise terms in your calculation from the second formula.

Shade

[shade]

I have some good news and some bad

As LF suggested I did some testing,and here are the results:

-Civ2.42
(small map/2 civs/no barbs)

First the formula
(THB+TRC+4)/8

-THB:Trade Home Base
-TRC:Trade Recieving City

This seems to be correct but there is one little thing that should be added: all modifiers seem to work on the truncated value of this formula.
==>Trunc((THB+TRC+4)/8)
(this means 2,001=2 and 2,999=2)

There were 5 cities
Washington(W)(1),Boston(B)(1),New York(NY)(2)=>1 counrty
Kyoto(K)(1),Osaka(O),(2)=>second counrty
(1) and (2) indicate the island they're located on
(letter)=shortcut for the name used lateron

Trade=route direction
wanted=if the tradecommodity is demanded by the reciever
Formula=basic calculated value
Arrows=tradearrows in the game
Mod's=modifiers that are in use

Trade |Wanted |Formula | arrows | Mod's
----------------------------------------------------------------
W->K | Y | 4,375 | 4 | none
W->B |N | 5,25 | 2 | My Cities
W->NY | Y | 6 | 3 * | diff continent/My city
W->O | Y | 4,75 | 4 * | diff continent
-----------------------------------------------------------------------------
W->K | Y | 4,875 +| 6 | roads
W->B | Y | 7,5 | 5 | roads/My Cities
W->NY | N | 6,75 | 3 * | diff continent/My city/roads
W->O | Y | 5 | 5 * | diff continent/roads
=> roads on diff islands mean that both cities are surrounded by roads,but there is no connection
-----------------------------------------------------------------------------
(using different amounts of starting trade from both cities)
W->B | Y | 7,5 | 7 | roads/RR/My Cities
W->B25,25| Y | 6,75 | 6 | roads/RR/My Cities
W->B19,16| Y | 4,875 | 4 | roads/RR/My Cities
W->B22,19| Y | 5,625 | 5 | roads/RR/My Cities
W->B44,42| Y | 11,25 | 11 (12)| roads/RR/My Cities
W->K | Y | 5,375 | 10(11)| roads/RR
W->K | Y | 6 | 15 | roads/RR/Super Highway

conclusions:
*=> different Islands DONT give any bonus
+=> shows that the value from the formula is truncated before further calculations(4,875x1,5=7,3 <>6!!!!)
=>since a RR square is always roaded(check it uot yourself using the cheat mode) I would say RR gives a bonus of 100% instead of having to take in account the fact that there are roads underneath them=>ie 2x+50%

Also am I very sorry to say that the modulators are used like this:
(((Formula)xM1)xM2)xM3
(and in those calculations there are no truncations until the final solution)

Also there still are some small discrepancies,look at the last tabel there the game values are 10 and 11 and the calculated values say 11 and 12(and I can't figure out where they are lost,it's not truncation,I'm sure=>calculated them)

Also an other little sidenote: 2 cities connected through roads does not mean you get +50% there seems to be a favored road(probably the one the AI would use in a go order )

Shade

[shade]

this is the test'game' I used

(couldn't add it while editing previous post, my white-spaces in my tabels are gone )

Shade

[SlowThinker]

Shade,
Welcome to the club of testers

I agree there is no different continent bonus and no freight bonus.

Two cities at a straight distance 3 get a road/railroad bonus only if there is a road/railroad with a bend.

And road/railroad routes are one-sided! Only one city gets a bonus. The (opposite ) route needed for the bonus of the second city is different.

I started with Scrolls of Ancient windows (Is there some better summary about the permanent trade bonus anywhere?).
The text about superhighways (Superhighways in home city...+50% ) is a little bit confusing. It is not the home city of the caravan that gets a bonus. It expresses that the superhiways needn't be in both cities (as airport) - only the city that has superhighways gets the bonus.

---

Originally posted by shade
SID ACTUALLY USED A REALLIFE POPULATIONGROWTHALGORITHM

I agree that the formula is for a limited food.

But:
1. I don't think it is natural real life: More food is usually available, but for higher expenses.
2. I think Sid didn't choose that formula. The civ city growths slower and slower, but don't stop growing.

[shade]

didn't test for freights and airports

1. I don't think it is natural real life: More food is usually available, but for higher expenses.

the formula I gave was a simplification used for simpel pop models(as is the exponential growth)and they simulate real population models.(but in a simplified way)

2. I think Sid didn't choose that formula. The civ city growths slower and slower, but don't stop growing.

1) the actual model I describe only reaches the limit at infinit(ie it never stops growing)it grows asymptotically.
2)It will not be exactly the same but it will be very close(eg the last time your pop grows 1 point is like 200 turns or so)
I have some graphs of it at school,I'll post it here(exel),it really shows the curve the described formula has.

Shade

[SlowThinker]

Originally posted by shade
the actual model I describe only reaches the limit at infinit(ie it never stops growing)it grows asymptotically.

do you speak about this:
dN=a*N*(1-N/K)

If you suppose you have always 2 food per square then
dN=K /(1+N)
(1/1+N represents the size of foodbox
K is a constant)

[shade]

do you speak about this:
dN=a*N*(1-N/K)

Yes.

btw I took a city with only grassland around and farmland=>4food/sq
Here you have to keep inmind that K isn't always constant(it grows with the population (for a while).
i'll add the exel-thingy I created.
(when you take a look at the graph you see pop/time.
When you plot that differential equation you'll get something similar)

Shade
PS:I forgot to take a look at it at school,and on this computer there is no exel so I'm not sure what the last graph was I saved