Before I make my criticism, I want to make something very clear: there is much that is laudable about Azual's post: there is a clear statement of methodology and the construction of hypotheses designed to test a premise that are clear, cogent, and repeatable. All of the basic foundations of his analysis are present and correct. Azual's post is not bad science by any measure that you see around you in the real world. No person reading his post should ever for one moment think "this is a bad way of doing things". It isn't. His opinions are clearly separated from the data which he collects and analyses and at no time does he try and state that one is the other. This is rarely found in today's world, and should be held up as a good example of others. It was, for me, lacking one crucial ingredient, and this will hopefully become clear as I fill in the approach I took in checking the analysis
Theoretical Analysis
There is a glaring preface I need to make to this. I have approached this purely from a mathematical treatment. I haven't even logged into Eve in order to test these numbers - this is a spherical cow analysis designed to isolate the important behaviour without extraneous variables. Weaknesses in the analysis can therefore come from three sources:- Mathematical error - It's been a long time since I left university. Even if I did spend 9 years of my life there in labs and in front of analyses, I'm rusty. Even if I wasn't, don't take what I say as gospel. That's bad science. Check for yourself.
- Exclusion of "real world" considerations that have material bearing on the behaviour of the model - as the people who pioneered QED found out: your theory may produce some of the most precise agreement with experimental measurements that has ever been, but if it claims that all of your particles have zero mass when they clearly don't, then there's something missing
- I got a formula wrong in my spreadsheet. Never discount human error.
Expectation values and DPS
What I found missing from Azual's analysis was any discussion of expected DPS. Firing guns at someone is a probabilistic event which I am modelling as a single event independent of gun grouping. As per evelopedia I am defining the applied DPS, based on a base DPS Do as followswhere x is a random number generated in the range [0,1[
Pcrit is the probability of a wrecking shot
Phit is the probability of the shot hitting.
Note that this is explicitly for the condition
The opposite case I'll mention later. The question then becomes, given the model defined above, what is the expectation value of D that we can expect? I'm going to define this as the sum of two sub-terms, W (for wrecking) and S (for standard), and talk about each one separately.
Random numbers and binning
I'm going to assume that the random number generator is perfect in terms of quality, but that it distributes numbers in bins of width k and treat this as a finite discrete series of data rather than a continuum. This simply is an acknowledgement that numbers are generated to a finite number of decimal places, and the change this makes when comparing to a continuous distribution. If we convert the second case (S) where the random number lies in the "normal hit" range, then we note the following:- First value of x: Pcrit + k
- Last value of x: Phit
- for each bin, i
where Nb is the number of bins in the range we care about. This allows us to derive the expectation value term S.
which if we expand out Nb
Finally, in the limit that k tends to 0 (which is almost true) we can write S as:
The derivation of W in the same condition is trivial, and not included here. We will merely state it as
allowing us to state the expectation value for the DPS as follows
This gives us a baseline estimate for comparison of different turret types for instances where the probability to hit is greater than the wrecking hit chance. In the case where this is not true, it is trivial to see that S=0 and W only applies (up to the point where x=Phit and is 0 otherwise).
Evaluation
Having constructed a workable formula, let's apply the situation as tested by Azualit should be noted that I got the raw DPS figures from pyfa and the fits provided in Ripard's post. Everything else was sourced from Azual's analysis. The actual value of the DPS figure is less important than the values relative to one another (because of resists etc that will change the applied DPS).
At first blush, this seems like a solid confirmation of Azual's analysis. Everything is as you would expect. What caught my eye, though, is that Azual made the choice to substitute the Uranium in Ripard's fit for Iron. Without wanting to put words in Ripard's mouth, a reason to choose Uranium is that the optimal range is the same as a Ferox with spike. Of course this might not have any effect, but this needs to be established.
As you can see the picture is quite different. The larger guns are performing significantly better against a small mwd target (even with tracking computers) than the large guns at the 60-90km range, but the signature of an mwd cormorant is large, so this is not unexpected. The results at 300m/s (and 90 sig radius) are as follows
Iron Naga - 300m/s |
Uranium Naga - 300m/s |