Factory output

[Astral]

How do you calculate the real shield production of a city?

I see it like this (but never tested it in game) due to the discription of the different plants.

Base output = 10
Factory = base+base*0,5 = 15
This is common

Now here comes the tricky part. In the civ.opia. it says:
"Increases factory output by 50%." (or 150% with nuclear powerplant) but how is this to be understood?
Is it: 10 + 10*0,5 + 10*0,5 = 20
Or: 10 + 10*(0,5*1,5) = 17,5
(the last is: base + base*(factorybonus*150%) where 150% is to increase factory output, which is 50% of base, by 50% as the powerplant does)
Said in another way:
10 shied is base, then we have 5 shields extra which comes from the factory - this must be the "factory output", this should then be multiplyed by 1,5, so that it (only the factory output) will be added the 50% that the civ.opia. says a powerplant adds.
But what is the real calculation?????
(If you understand what the hell i've written)

 

[Psychlone]

My brain hurts.

What I'd recommend is that you reverse-engineer your problem. Take a city with all the improvements, see how many shields it creates (don't forget to add corrupted shields, too), and then compare the total to the actual shield value of the terrain. Once you know the basic "unenhanced" shield value of the landscape it should be easy enough to figure.

My personal opinion (now I'll have to check, damn you! I hate mathematics) is that it seems to be compounding. Each additional shield bonus improvement multiplies off the current total, because it's possible to get cities kicking out in excess of 200 shields per turn, and if you figure the average city radius is probably only going to have an unenhanced shield value of 25 or so (that's a pure wild guess figure thinking of grasslands with a few bonus shield squares and a hill or two plus railroads), that's a lot of increase.

(added in edit)

I just checked a city on a saved game. The base shield value of the city radius terrain was 26 shields. The city had the iron works, which is 100% bonus. Perhaps I'm calculating that wrong, but that should double the shield output to 52. The actual output was only 42 shields.

I added a factory, which increased the output to 58 shields (city also has a hydro plant bonus provided from Hoover Dam). Now by the calculation method I mentioned above, I came up with an expected total of about 88 shields. So my new theory is that bonus shields are not further multiplied. Apparently this seems to apply to the railroaded mine bonus as well, because my numbers were off from the very first step. I'll have to look again later, I need to head to work now.

 

[History_Buff]

I thought it was 50% for factory, and 50% for one power plant, plus 50% for the manufaturing plant. These are cumulative, so double the original number of shields, and add half. Should you have an odd number when it comes to add half, round down.

Also double the number if you have the Iron Works there.

 

[Astral]

I think I must make a test...