Population Model v. 0.1

[amjayee]

About connection speed; actually it is not any slower to load the page than on other sites, but sending messages takes much too long. I have been using 128 bit ISDN. All Finns and Swedes using ADSL? I wish that would be the case! Well, ADSL isn't very expensive anymore, but it is not used very widely yet. ISDN is currently quite popular here. Swedish government is about to start building a national network of optic fibre, connecting all households to Internet with fast connections; something to be envious of, as it sounds now. But no one knows what technology is invented tomorrow. Optic fibre can become obsolete soon.

In Finland, we are concentrating in wireless communication. In Helsinki University of Technology, where I used to study, they have built the first wireless network in the world; I have heard it is actually quite fast, capable of showing live video picture. I believe that's what the future of Internet is. Personally, I have a small handheld computer with connection to Internet via a mobile phone. THAT connection sucks, but I can use WAP and email with it. So that's the difference between Sweden and Finland. Time will tell who is foreseeing the future best and making the right investments...

Ok, that was off-topic; but hey, perhaps that could belong to the demand of communication technology stuff. About sub-ethnicities; like Joker said, most regions will have its own ethnicity, it's just that the ethnicities are so close to each other the differences are insignificant. In Finland, the people of different provinces are quite clearly different from each other, and we speak our language in clearly different ways; you can tell from the speech of a person where he is from. Still we are all Finnish and equally patriotic. The situation is same in many other countries too, I think. More sensible thoughts later...
[This message has been edited by amjayee (edited August 29, 2000).]

[The Joker]

Guildmaster:

You can change your signature at the top of the forums list. In the right side of the screen there is a small link called Profile. Click it and it will take you to a great place where you an change your signature, your password and all sorts of things!

My connection is just a plain old 64k ISDN. But I wouldn't be surprised if Amjayee and all other Fins have some hightech 10Mbit ADSL line. Sweden and Finland are simply the best in the world when it comes to communications.

I would like to have an ADSL line, but unfortunately they are really expensive in Denmark (the cheapest 256k lines cost about $50 a month). Since Denmark is about 3 years behind Sweden in communications ADSL lines will propably be cheaper than ISDN in a year or so.

Sub ethnicity:
I don't think we need to actually name the subethnicities. But each province would pretty much have it's own ethnicity. It would just be really similar to that of the civ controlling it.

transportation and communications:
Of cause these should have a huge effect. Fast communication and transportation is what makes large empires stay united today. But I think there could be better ways to do it than simply to have a default demand for each type. I think it should be a little more complex. Although I am not really sure how to do it right now.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[Guildmaster]

I actually don't feel so backwards now, to know that everyone who lives on campus here has 10Mbit ethernet for free unfortunately I just don't live on campus. Cox cable is slowly hooking up ethernet to the surrounding areas and that's only $20 or so a month, but you have to have an account with the university. I don't want to talk to Cox though because I owe them money which I don't have so even if they do hook up my apartment I won't be able to turn it on for a while. That's ok though since I no longer have a computer anyway... I just use the ones at school with the ethernet.

As for ethnicity... I am remembering from clas syeserday the guy was lecturing about the causes of the first world war and as I was about to say I don't think ethnicities should play a major role in actual gameplay I am rembering my notes from lecture. It seems that's what the whole thing was all about in the first place.

[Guildmaster]

Korn:
Look at the economy thread, we're saying that each good falls into a category of goods and a greater demand. Your bullet train example would satisfy a transportation demand that is met with automobiles in other countries, etc. PCs would be needed for internet access perhaps in some countries because the communications demand requires the latest greatest technology for that while in another country the communications demand is met with a mail-carrying mule going from village to village.
This isn't so much a cultural thing I think as it is a matter of relative circumstance: Case in Europe while the geographic area is only slightly larger than the US, there are three times as many people in Europe as there are over here. People spread out more and therefore public transit is impractical. The transportation demand still needs to be met, however, and therefore people buy cars instead.

[The Joker]

Guildmaster:

Why excactly shouldn't ethnicity play a large role in the gameplay? I'm sorry, but it seems like you have written your second last post in a great hurry. I really have trouble figuring out what you mean...


Korn:

I think Guildmaster explains pretty good. I agree with him, it should be the circumstances rather than the actual culture of the civ that determines what good it's people buy. But of cause it would be obvious for dictatorial regimes to ban PC's. This would more be something the leader decides than it would be a thing determined by the people's culture.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[korn469]

here's a thought...

maybe each culture could have it's own demand of goods which would be dependent upon it's technology level and government type.

so lets say we have a group f various cultures

if they each had had the same government/economic system and technology level they would still have differences in their demands for goods, this would be random and could have lots of little factors thrown in. for example in a dictatorship personal computer use could maybe be outlawed and there would be very little demand for personal computers, while at the same time the government might be conducting military research and the demand for supercomputers could outstrip supply (real world example: the soviet union circa early 80's), while in other part of the world two countries with equal tech and government systems could have very different demands (us no demand for high speed passenger rail, europe and japan high demand for bullet trains)

as they say the devil is in the details and if we get the details right we should not have anything to worry about

korn469

[The Joker]

This thread has been passive for too long. Many of the features in Amjayee's model are really quite advanced, and we really don't need them right now. What we do need right now is a pop model with the ability for people to live, have kids and die, so we can link it to the economy model and have an active people that can work independantly and function like we want them to in the game. When we have accomplished that we will have gotten far!

I therefor think we should develop such a simple pop model, where nutrition (amount of food eaten) and tech level effects mortality and education effects birth rate. No need for ethnicity, professions or any other high end stuff. Linking this basic model to the econ model shouldn't be too hard.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[Ramo]

Hmm.. I generally hang out in the OT, so I don't know the backgroud behind your project, but here are a few observations:

Births:

Barring major epidemiological disasters, population growth has generally been exponential. Because the instantaneous rate of change of a population, WRT time, would be some function, c(t) (which would represent the percentage of pregnant people - probably peaking in the Modern era, and going down as people get birth control), * the population, P. This would give the relatively simple differential equation:
dP(t)/dt = c(t)*P

The equation would, then be, P(t) = Po*e^([integral]c(t)dt).

I suggest that your model follow a similar function.

Mortalities:

This is a biggie, and would be really complex.

Microparasitic influences should be adequetely modelled. For example, trade with other civilizations could often be disasterous (Rome fell preciesely because of small pox, measles, and later, the bubonic plague, it acquired from trade with India and China...). So, if you meet a fairly advanced civ without adequate medical/genetic safeguards, you should lose huge chunks of your population.... As long as your civ has constant contact with a micro-parasite, it could be kept as a "child-hood disease," and wouldn't affect your vital work force that much - only increase childhood mortality.

Other than diseases, mortality should be fairly simple to calculate - simply adjust it based on factors such as medical technology...

Classes:

There shouldn't be a static class list because classes change with different economic and political systems. For example, a capitalistic society would have no nobility, but would have industrialists, a socialistic society would have no classes, etc....

Hmm... that's it for now..

Hope this helped.

[amjayee]

Joker: I agree. I will think of it, and possibly try to make a simple computer program running that kind of model. I will post any results I get.

Ramo: The kind of equation you proposed has the fault, that even though the general population growth follows some kind of approximation function, it cannot be simplified that much without causing some problems. In the game, every turn must be found out, how much new births occur, and how many deaths. Those rates are affected by many things. Also it might be possible that in some other world the population growth would go quite differently from our world. But I think you are correct in that we might use some mathematics to find out, how we should emphasize the things affecting the population. That mathematics we need to do ourselves, and only use the results to build the model, I think. Anyway, I don't want to program a model that needs to solve differential equations.

And about diseases, those we already have. There shouldn't be any things that always happen automatically when you do something. With the diseases, if you meet a civ with bad helath care and diseases running rampant, their diseases might spread to your area, and then start killing your people.

[Stuff2]

About storing numbers for population.
This is just an idea

All you need is 5 chars.

The first 4 is for a number and the last char is for number of 0 after. like this:

13680 = 1368
24953 = 2495000
02372 = 23700

The effect is that you can't get specific numbers above 9999 but you still get numbers that are manageble when counting changes.

[amjayee]

Stuff2: That method has a problem: 5 chars would mean 5 bytes, and with them we could store numbers from 0 to 9,999,000,000,000 with four significant numbers. But if we use unsigned integers, with 4 bytes we can store numbers from 0 to 4,294,967,295 with 10 significant numbers; that should be enough for most occasions, at least for province populations. And if we use float variables, with four bytes we get six significant numbers multiplied with as many powers of ten we will ever need. Your idea is not bad, but there are better methods. Using characters wastes a lot of space. Plus, in provincial scale, using your method would not be accurate enough. It is important to count their population amounts accurately.

[This message has been edited by amjayee (edited September 25, 2000).]

[The Joker]

Ramo:

Welcome on board!

Currently our main tasks are to design and later program the population and economy models. I think we have a way to store the map, but I guess some programming there is still needed. Apart from this there is always the User Interface, which of cause is important.

It is totally up to you what you want to do. Everything will be helpful.


Stuff:

Welcome on board to you too!


I would like to reply on the posts here, but I am simply too tired right now. I will go to sleep and post again tomorrow.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[Ramo]

amjayee:

quote: The kind of equation you proposed has the fault, that even though the general population growth follows some kind of approximation function, it cannot be simplified that much without causing some problems. In the game, every turn must be found out, how much new births occur

Ummm.. that function was meant to calculate births...

quote: Those rates are affected by many things. Also it might be possible that in some other world the population growth would go quite differently from our world.

Exactly, which is why I gave no definite value to c(t). Basically, c(t) can simply be a constant, calculated every year, where t is a vector representing all the different aspects of a civ, at a given time.. For example, if the birth rate is .05 at a given year, the new population, without moralities, would be P(e^(.05)), the next year... I'll revise c(t) to be simply c... That year, the birth rate would be recalculated, and a new population would be given...

quote: But I think you are correct in that we might use some mathematics to find out, how we should emphasize the things affecting the population. That mathematics we need to do ourselves, and only use the results to build the model, I think. Anyway, I don't want to program a model that needs to solve differential equations.

Right. You certainly don't need a differential equation solver, because it's the same dif. eq. for all cases, and could be solved by seperation of variables, giving: P = Po(e^(ct).

Joker:

You said that the project would be renamed "Guns, Germ, and Steel." Does this mean that you will take into account environmental factors in the development of a civ? Because, that would screw over players that started in a thin continents, without many domesticatable plants and animals...

[The Joker]

Births:

Yeah, I think that makes sence. Who would have thought math would be this useful?

Check out my age groups model in this thread from August 24. In there I have tryed to create a way to calculate excactly what the growth rate should be, by including a number of simple variables, such as mortality for each age group, number of kids per family and the age where people have kids. I think it would be pretty functional and accurate. It doesn't really include an exponential function, since the change in pop is just calculated every turn, but when looking at a number of turns the result would be an exponential function. What I like about the age group model is, that it makes it possible for different societies to have different growth rates, even if their population is the same. Therefor I think using an exponential function would propably be too simplified. If this was to be used the function C(t) should be effected by a large number of variables, which would propably end up making it easier to just include the variables immediately and calculate the birth rate using them directly.


Enviromental factors:

We haven't talked about including plants and animals in the game. I think it would propably make the game too complex. And as you said it would mean that civs stranded in unlucky continents would have a really poor start.

But what we are trying to do is make this game far more dynamic than previous civ games. The rise and fall of great powers idea is something that we will work towards implementing. Therefor it wouldn't really matter in the long run if your civ never really accomplished anything before 1000 AD - it should be possible for mighty civs to collaps and small civs to rise to glory all in just 100-200 years. This should make the game thrilling all the way to the end, in stead of a Civ2 like world where the game is settled by 500 AD.

Of cause when all this is said I must also say that I agree with you: We shouldn't have animals and plants in the game.

BTW: I am in the middle of reading Guns, Germs and Steel. Great book! It is really the most interesting history book I have ever read.

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"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[amjayee]

Yes, population growth has been exponential for all history of mankind. But, until 19th century, the population amount remained somewhat constant, or actually rising linearily with quite small inclination. That was because of wars, diseases and famines.

What I meant with my previous post was, that every turn must be considered individually. If the amount of people (or the amount of people at the reproductiive age) in some area is x, the amount of new births for that turn is c*x, where c is some constant. Repeated turn after turn, while the amount of reproductive people rises, the population grows exponentially; though for a long time, the amount of reproductive people rises only very slowly, or it could even decrease.

What c is, depends heavily on the type of society at that moment. That in turn we are going to model with a system called "technology level". For each technology level we would determine how it affects he society. Also some temporary events might affect; some historical situation might cause a "baby boom" for example. Technology level things would be pre-determined and balanced.

Technology level effects would of course be combined from many factors. Some society might have technology level properties x and y. They would affect population growth by x' and y'. Now, depending on the case, we might have that the combined effect is the sum of x' and y' or, the average of them. With population growth, we would usually use average, but we have to see.

The reason for such a simple system is, that the population growths might be calculated really many times per turn; if we reduce it to a single multiplication, we save processor time. This is also only appropriate, since in the game we will deal with turns. We need for each turn to take into consideration certain fixed set of variables, each having a simple way how to take it into consideration. That way, they are simpler to program, simpler for the computer to execute and also simpler to balance. Also a turn is considered as one single moment of time, effecting the overall timeline of history with certain constant effects, resulting eventually in realistic enough changes over time.

Ramo's function could be used to determine the constants for each technology level. Also otherwise, mathematics is good for analyzing certain things; but in a large program like this, with dozens of other tasks also to take into consideration, we need to keep the maths simple.

Sorry for the bad replies I made earlier, I was in a hurry. Welcome to our little team, Ramo and Stuff!
[This message has been edited by amjayee (edited September 27, 2000).]