Talk:Zombie Skills/Scent Death

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Iwitness Records that show scent maps

Case 1

Case 1 Analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies
255.255 255/79 255/48
255.255 255/251 255/?
This data is from the BB2 siege at Giddings Mall. I think its safe to assume the numbers of zombies and bodies there would "peg the meter", so in terms of ratios, these values are probably meaningless. For example, if one zombie or body adds 6 to the respective chroma value, all expected values would end up over 255 in this case.

Case 2

Case 2 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies
54.24 54/10 24/?
57.29 57/8 29/6
69.43 69/13 43/7

Case 3

Case 3 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
15.10 15/1 10/2 Direct observation. Building type = NT.
15.4 15/0 4/0 No zombies or dead bodies observed inside or out. Building type = warehouse. "Salt" effect?

Case 4

Case 4 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
40.86 40/7 89/? location = open street, revive point
15.4 15/1 4/? location = open street
30.3 30/4 3/0 location = motel

Case 5

Case 5 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
12.17 12/1 17/1 location = ehb bank, assumed no z or b inside
9.0 9/1 0/1 location = ehb building, assumed no z or b inside
48.40 48/9 40/8 open block. 7 of 8 bodies "smell funny"
142.152 142/28 or 30 152/31 location = ruined hospital.
Zombie numbers changed during observation.
2 bodies smell funny.
128.99 128/25 99/17 location = ruined NT. NO bodies smell funny.

Case 6

Case 6 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
7.34 7/0 34/6 empty block, revive point, 2 bodies smell strange
12.27 12/3 27/3 motel, loose cades
1 zombie out / 2 in
2 bodies out / 1 in

Case 7

Case 7 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
13.7 13/0 7/1 NT building, ehb, no z or b inside, self in block
3.4 3/0 4/1
9.43 9/0? 43/7? auto repair, vsb, did not check inside
2.1 2/0 1/0 carpark
0.10 0/0 10/0 towers, vhb, did not check inside, some delay after scent map made
7.9 7/0 19/0 same block as above, smalled after moving, self in block
52.48 52/8 48/9 NT, EHB, 2 funny smelling bodies
27.18 27/5 18/2
8.33 8/2 33/4 ruined PD, all outside
15.44 15/1 44/8 EHB police dept
33.10 33/6 10/0 lightly school
64.80 64/11 80/14 Ruined PD, all but 2 z's outside
24.31 24/2 31/7 hb FD, 2 funny smelling bodies

Case 8

Case analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
22.28 22/2 28/6 self also present as zombie
25.65 25/5 65/11
26.6 26/6 6/0
27.21 27/2 21/4
36.70 36/5 70/11
0.54 0/0 54/8
18.16 18/2 16/4
35.7 35/7 7/2
2.43 2/0 43/7

Case 9

Case 9 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
11.255 11/1 255/50
2.40 2/0 40/6
8.0 8/2 0/0
0.0 0/0 0/0
9.20 9/1 20/2
42.7 42/8 7/1

Case 10

Case 10 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
45.30 45/6 30/?
21.9 21/1 9/1 self also at scene as zombie

Case 11

Case 11 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
39.16 39/5
13.1 13/1 1/0
32.46 32/5 46/10 was 33.47 from another location
54.47 54/12 47/9
42.4 42/7 4/1
61.59 61/13 51/9

Case 12

Case 12 analysis

SIM Core Map.png Swiers
g.r values g/zombies r/dead bodies comments
8.26 8/3 26/3
3.21 3/0 (plus self) 21/2
6.0 6/1 0/0
78.18 78/15 18/5
30.20 30/6 20/2
17.42 17/2 42/7
28.37 28/4 37/5

Case X

Case X analysis

~ ~ ~
g.r values g/zombies r/dead bodies comments


I'm pretty sure color is not just made of Z number and B number. I suspect that it is based on certain number fixed to location type that is then added with the Z/B mix. Also It might not be just bodies, but Dead bodies and Reviving bodies (B=DB+RB) that are taken in account. don't forget that previously Scent told you from where the smell of reviving bodies come from, i'm sure this is still shown --~~~~ [talk] 18:52, 25 January 2008 (UTC)

Yeah, its probably not simple. It does seem that even empty locations are perhaps not solid black.
The table I did above for case 2 probably over-simplifies the situation; I should probably break out inside vs outside, and "funny smelling" bodies vs normal dead bodies. And once I DO have data, I have no idea how to run a regression on it. Anecdotal evidence may be equally useful, given the complexity.
To really test if you theory about location types is true, I'd probably have to modify my ScentMapNumbers Greasemonkey extension so that it also shows the location type (and perhaps name)- not an easy task, but probably useful in the long run. SIM Core Map.png Swiers 19:08, 25 January 2008 (UTC)
by location types i mean... imagine a necronet scan. then desaturate it and hue to green. then decrease brightness. that's it. now add red and yellow to where the "scented targets" are and we're done. --~~~~ [talk] 19:14, 25 January 2008 (UTC)
Maybe, except there is never ANY blue chroma that I'm aware of. The code instances I looked at had none, so I didn't bother including it in my extensions displayed values. Granted, the game doesn't use much blue to begin with, and it may be blue gets damped more than other colors. Anyhow, if this is true, the values may be low enough to treat as random noise; I doubt any building type contributes as much chroma as even a single zombie or dead body. SIM Core Map.png Swiers 19:21, 25 January 2008 (UTC)
desaturating and hue to green won't leave any blue. anyway the theory that this salt is just random noise can be easily checked... i really need to stop talking about it and actually log on to the game and just try out myself... --~~~~ [talk] 19:27, 25 January 2008 (UTC)
Apparently if you do a scent death, move to another square, and then move back and do it again, the values will change even without any observed change in zombie / body numbers. That would lend weight to the "random noise" theory. SIM Core Map.png Swiers 00:52, 26 January 2008 (UTC)
Actually you don't need to move to another square. Just take scent from same place twice in a row - you get a different picture. This proves that the random salt as added. --~~~~ [talk] 22:08, 30 January 2008 (UTC)


Graph of zombie numbers by green chroma value: It looks as if each zombie adds 5 to the green chroma, with a fair bit of noise seen at lower values. A random value for +1 to -1 added to the number of zombies would reasonably account for this noise for the data gathered. The fit to this formula seems very tight, up to the point where you have more than 50 zombies (which simply yields values of 256, no shown on the graph). SIM Core Map.png Swiers 01:54, 13 April 2008 (BST)

Graph of body numbers by red chroma value: It looks as if each dead body might also add 5 to the red chroma, but the seems to be much more noise and a less tight fight. Its possible that "funny smelling" bodies are counted differently from normal, or that the data is otherwise flawed. SIM Core Map.png Swiers 01:54, 13 April 2008 (BST)

Furthur Analysis

So, with all this analysis having been done, I though it would be an idea to make a small program able to analyse the SIM images and return some zombie and body values. Given sufficient SIM coverage the reports could even be relied upon to some extent to provide suburb news reports. EG: "Latest SIM data suggests 40 zombies and 20 bodies in the suburb" Program in the RPs and you even get something like "10 of those zombies are standing at designated revive points, 15 of those bodies are also in these zones"

Anyway, I got everything up and running and decided to do a cross-reference with an EMR to see how accurate the info was (Seeing as EMR's are objective as far as is known)

I searched the records and luckily an EMR for Jensentown came in at about 09:00 on May 19th, SIM images covering the area had been posted just hours before.

The Report

10:37, 19 May 2008 (BST) 25.96 MHz: "... can see thirty or so on the streets of Jensentown ... mostly just stragglers, no organised groups ... several buildings with power ... only a few buildings damaged ... lights are on in the Shears Building ..." (1 hour and 48 minutes ago)

SIM Images

SIM record from 5-5, covers leftmost part of Jensentown

SIM record from 16-5, covers most of Jensentown

I chucked the two SIM images into the program and had it return values for blocks lying within Jensentown only. It return values of 138 zombies and 163 bodies. (Given a 1:5 ratio of things to colour as you've all established above)

Somewhat more than 30 zombies at any rate. Even if EMR's actually only report numbers on the streets, that would mean 110 zombies had somehow hid themselves inside buildings in a generally safe area at the time.

I checked the maths, the SIM does have a total green value that divides by 5 to give those numbers, but that's much higher than the EMR states.

On the flip-side of things, if there were only 30 zombies in the whole suburb, then they'd produce a total green value of just 150. That's only enough to light one square with 150 out of 255 max. All the other squares would just be black as far as zombie counting goes. Or if they spread out they'd still only cover 30 of 100 squares and they'd be a pitiful value of 5 eachy. They'd still be too dark to make out.

Granted, the nature of EMR's and SIM images means that the former generally reports lower than true numbers in total, and the latter reports greater than true numbers in total (For all of Malton)

But, we're talking a specific region with reports for more or less the same time. The numbers just don't add up. Anybody able to figure out what's going on? Am I missing something obvious here? -- User:The Rooster RoosterDragon User talk:The Rooster 14:35, 21 June 2008 (BST)

There's a lot of "false positives" at the low end of the scale- the correlation is much less direct for lower color values / zombie numbers. Try treating all values less than 10 (or some such) as being 0, maybe? Those "false positives" never made it into my data because I only recorded the chroma values for blocks that DID have zombies in them, not for empty blocks. Still, if you look at this graph you can see how the color values are skewed above the "5 per zombie" ratio when the numbers of zombies are low. Or you could treat the number of zombies as being (green chroma-5)/5, perhaps. You'd get occasional negative values, not sure if you'd want to discard those or factor them into the total as a balance for the over-counting. SIM Core Map.png Swiers 19:54, 21 June 2008 (BST)
PS- You might be interested to know that the database driven version of SIM is coming along nicely, though its still far from done, let alone being on the public host. Once done though, it would be able to supply data for this sort of analysis very easily; I'd just have to host a page with a CSV dump or some such, or even build some analysis features into the map page. SIM Core Map.png Swiers 20:15, 21 June 2008 (BST)
Jeez, it's salt that was discussed above. Just take 2 scents in a row from the same place - they'll be different in the "lowest values". You can't use these errors as hard steel data and make estimations based on it --~~~~ [talk] 20:19, 21 June 2008 (BST)
Post edit conflict: I relise it was the salt, although I don't seem to have made the right assumption about how it operates. It seems to be more complex than just adjusting the end value by a small amount in either direction. Maybe it also boosts things by +5 on occasion? Pre edit conflict: I apply rounding to any value given after dividing by five. Provided the salt was no bigger than +/- 2 for the for the croma this would account for that random factor in its entirity, even a blank square managing to boost it's value by +2 would be put back down to zero as it would have .4 of a zombie which rounds down. If the random factor isn't this simple, and blocks can gain entire levels easily, we're still looking at an average level gain of 1 zombie per square just to come close to balancing things. If somebody could spam Scent Death like 3-5 times from the same spot in quick succession and save each image, then that's some handy statistics right there and nailing down the random factor would probably be much easier. Even more-so if the same person reports the zombie/body count (or lack thereof) in a few of the outside blocks (Streets, parks, wastelands etc) nearby so it can be seen if empty ones gain a few zombies or bodies by magic. It probably is more complex like you suggest, body counts seem even more varied. The map also seems to report more of them than zombies, which is odd because I don't think I've ever actually seen bodies outnumber standing zombies on the stats page, even with the low zombie ratio of recent days. Anyway, that SIM database sounds awesome, hope it works out. -- User:The Rooster RoosterDragon User talk:The Rooster 20:47, 21 June 2008 (BST)
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