The IAGA database available through NOAA is out-dated, so don't use it.
The most up-to-date version of the database for your time of interest can be found here http://geomagia.gfz-potsdam.de/
There are two databases, one based on sedimentary analyses, which yields only inclination and relative...
Hi Stephen
Thanks for the reply. This distribution was used is a piece of software and the previous snippet was from the manual. I have tracked it back to the original publication and it looks like the author derived it themselves. You were right, though, it appears that they have started from...
I am looking for more information (e.g., reference, the CDF and descriptive stats) about a four-parameter skewed generalized Gaussian (SGG) distribution. I have come across the PDF for this distribution, but with no reference and not a lot of other information. Here is a snippet...
On...
Been away for a periods, so sorry the lateness. Thanks for all the comments and suggestions. I have to put this problem down for a little while (other priorities), but no doubt I will be back with other questions!
Cheers
Geo
I've been busy programming up some code to crunch through both of these tests for a range of methods. It turns out both give pretty similar results in terms of the number of bootstraps where the selective method beats the random selection.
The method I suggested does tend to give a slightly...
If we use a Normal distribution to approximate the distribution of wins for a particular method, for a Binomial disturbed variable that follows B(k, p), where k is our very large number of samples and p is the underlying probability of success, the normal approximation is \mathcal{N}(kp...
The selective method assess all specimens and all fits to those specimen. In this case we have 400 specimens. If the no results are accepted from a specimen that specimen is rejected. Specimen are only accepted if at least 1 fit passes the selection process. So we accept N <= 400 specimens.
In...
Let me see if I have the practical application straight in my head...
We apply Method A and end up with N specimens that yield acceptable results. Each of these specimens yields at least 1 acceptable result. Our analysis procedure would then be
1) For each of the N specimens select 1 result...
Finally, some time to respond!
In the interests of simplicity, I think that this is a necessary assumption. For various physical reasons, that I'm not going to go into, this assumption may not be entirely valid.
Yes it is.
This is a physical possibility, but one that is difficult to...
Thanks for your comments. Today is a little busy, so I don't have time to respond in detail.
I'll digest what you have said and get back to you tomorrow.
Cheers
geo101
What I'm talking about here is the range of physical behaviour affecting the specimens. For some physical behaviour, some specimens will yield only accurate results, no matter how we selected the data. Others will yield only inaccurate results. By looking at a large number of control specimens...
How I am viewing the system is just as a binary accurate/inaccurate system, which for our control data set we can do since we know the expected answer (accurate is defined as being within a factor of 1.1 of the expected value). So the distribution of the slopes is not what I am looking for, but...
Let’s start afresh, keeping it simple….
So we have 2D data from a number of specimens and we are interested in the linear slope of these two variables. From each specimen we can make multiple estimates of the slope, depending on the choice of (consecutive) points we use. We have criteria that...
Thanks for the reply mfb
That makes sense, I was confused with the case where, say, P1=0, then the product of accurate probabilities is always zero.
That's just my bad wording, I do mean at least one.
What changes between Pf and Pf′ is the number of specimens and the number of results...
I’m working on ways to try and assess if data selection methods are capable of isolating accurate results (from a control data set) with respect to random selection and to compare the relative performances of different methods.
In the data set we have multiple specimens and each specimen...