Weapon Accuracy for Devices

[Symon]

Yes. There is a good way to determine the "accuracy" value for ALL the different devices. But you have said often before that you are math challenged, yet you want all this in terms of mathematical expressions. I am confused.

You say "draw a curve and plot points on the curve" doesn’t help you, but it is the simplist and easiest way to find what you want. It just takes a graph program, of which there thousands of freeware versions. You don’t need math, just point and click. If you wish to spend a few years researching data and formulating the results into the game algorithm, more power to you. But obviously, what you want is someone to feed pablum. But pablum ain’t in it.

Simple, cheap, and effective results come from plotting things developed by others and then picking off your desired weapon. Your mod will be better for it and have specs that are in conformance with the engine.

But if you want math, I would be pleased to give you math. Ciao. J

[GaryChildress]

Hi JWE,

Thank you very much for your reply. I'm OK with some math. I'm not very good with graphs, Cartesian coordinates and stuff like that. But if something can be rendered into an MS Excel formula then I'm all set. Basically I would just need mathematical formulas like the one JuanG gave earlier in this thread. So, for instance I took his formula below:



And came up with this in Excel:

=SUM(10.25*(B7/(C7^3)*(D7+(2*(SQRT(D7))))))

When I plug in the 16"/50 Mk7 gun with shell weight of 2700lbs and rate of fire of 1.8rpm I get 30.291703. This appears somewhat close to what stock AE gives for a value. So far so good. But when I plug in other weapon types like AA guns then I get really whacky numbers.

If I may get a complete list of which formulas work with which devices, then I'll be in business. I'll be happy to send my resulting Excel spreadsheets and formulas to you if you want. I don't know if you work with MS Excel using your formulas now but it really makes life infinitely easier, at least for me (especially given the fact that WITPLoad works with Excel). Basically it just becomes a matter of creating an excel list of weapons and stats, create a formula column and voila! Just cut and paste the results into a CSV file for WITPLoad.

[John 3rd]

Glad you guys are working on this again!

[Symon]

ORIGINAL: Gary Childress
Hi JWE,

Thank you very much for your reply. I'm OK with some math. I'm not very good with graphs, Cartesian coordinates and stuff like that. But if something can be rendered into an MS Excel formula then I'm all set. Basically I would just need mathematical formulas like the one JuanG gave earlier in this thread. So, for instance I took his formula below:

Hi Gary,

Not trying to give you a hard time, apologize if it seems that way. But the graphical solution is the quickest, easiest, and most efficient way of going about it. I’m just trying to get you to understand how things work and how to mod them so they fit into the game’s sweet spot.

Working the math runs you into places where certain things have to be assumed, and many columns are judgment calls. One has to appreciate when, where, and why certain values are adjusted, and understand how. This does require a bit of ballistics knowledge.

Why not let the people who live for this stuff do the work for you? Whether it’s mine or Juan’s the curves will be rational and smooth. We know where the end points are and where the sweet spot is. So why not just plot the results of the work that’s already been done for you? Put the gun caliber on the bottom and the parameter of the left.

You may well see 3 to 5 guns of the same caliber having different parameters. If it’s Alt you are plotting, the first order whizbang is muzzle velocity. So where does your MV come in? Pick the closest and go left and read off your Alt. If it’s Eff, first order is shell weight, so find yours and find a similar, go left read off your Eff.

Acc is a bear. I don’t think anyone can design a gun and define an accuracy characteristic for it. Not the South Africans and not the Israelis and sure not the US or Russians. It’s been done for a very few ‘standard’ models but only for test comparison purposes. What Juan and I both do is develop a mathematical expression, plot it and then “adjust” (i.e., normalize) the curve to a set of known points. Then we read along the bottom for caliber, go up to the curve, and go left for the value. Not something that works well in an Excel spreadsheet.

Rather than worrying about math, why not learn to plot? It’s what the people at combinedfleet, and just about everywhere else, do for inferences.

[GaryChildress]

I tried my hand at plotting a graph as best I can figure from JWE's instructions. This is what I came up with plotting a number of different gun calibers and accuracies from the AE editor. Is this what I'm supposed to come up with? [&:] Now let's say I want to determine the accuracy of the 11" guns on Scharnhorst. What would I do from here? Would I put a dot around the coordinates 11,32, meaning the 11" would have an accuracy of approximately 32 in game terms?

Man I'm lost. [:(]

[GaryChildress]

I tried something a little different. I based my plotting on a logarithm instead of a linear equation. And instead of using bore diameter I used Rate of Fire. Rate of Fire seems like it would be a better determinant of accuracy than bore diameter. I don't know. [&:]

Just the same I came up with a formula in Excel I can use. The formula is basically: y = 18.133ln(x) + 10.43.
Instead of spending a lot of time plotting and tracing numbers on a graph it still seems easier to me to just create a formula in Excel and let the spreadsheet do all the manual work.

I'm thinking I may just use a standard logarithm for all weapons, maybe adjust a little (i.e. fudge the numbers a bit) depending upon fire control system or something. But I would think 2 rounds per minute for an 18" gun is going to be similar to 2 rounds per minute with a 6" gun in hit probability. Of course there are probably a hundred different parameters that affect accuracy, stability of the firing platform, relative calm or choppiness of the sea, fire control system, barrel harmonics, size and speed of the target etc.

[inqistor]

And why do you want to reimplement those sides already done? You just quadruple your amount of work.

IIRC JuanG got new formulas for guns in his MOD. Just use them, and maybe ask him, if he can do also German, and Italian guns. After all, how much models do you need? Ten or fifteen?

[Jorm]

So the ships fire control / direction system plays no part in this, seems very odd

[btbw]

Sorry but what mean W, D and T in calculation and what in result?

[GaryChildress]

ORIGINAL: inqistor

And why do you want to reimplement those sides already done? You just quadruple your amount of work.

IIRC JuanG got new formulas for guns in his MOD. Just use them, and maybe ask him, if he can do also German, and Italian guns. After all, how much models do you need? Ten or fifteen?

More like 50 to 100. We're talking about new devices for Germans, Italians and French. I don't think I want to impose upon JuanG to do that many devices for me.

[GaryChildress]

ORIGINAL: Jorm

So the ships fire control / direction system plays no part in this, seems very odd

Fire control systems aren't separate devices in the editor. So if I wanted to factor in FC I would have to do one entry for the 5"/38 mounted on ships with FC system "A", then a separate entry for 5"/38s mounted on ships with FC system "B", then "C" and so on. So each single weapon would have to be represented however many times are necessary to represent every fire control system there was.

[RyanCrierie]

I looked at Gary Childress algorithm for computing accuracy:

accuracy = 18.133 * ln(ROF) + 10.43.

and modified it a bit for automatic weapons -- ROF for automatic weapons should be considered in "pulses", e.g. something like a 5 second burst; and converting ROF from Rounds Per Minute to rounds per 5 second burst goes like this:

ROF per Burst = (RPM/60)*5

With that correction factor, Gary's algorithm returns:

1.1" MG practical ROF (100 RPM ) = (8.3 rounds in 10 sec burst) = 49 Acc.
20mm practical ROF (285 RPM ) = (23.8 rounds in 5 sec burst) = 68 Acc.
40mm practical ROF (85 RPM ) = (7.1 rounds in 5 sec burst) = 46 Acc.

[Dili]

What is ln?

[witpqs]

ORIGINAL: Dili

What is ln?

I think he means "natural log" (log in 'e' as opposed to say, log in base 10).

[Dili]

Thanks witpqs.