WestDK. Chronology for the western part of Denmark; Jylland and Fyn, AD 200-1986, by The National Museum of Denmark in Copenhagen (WebCite-archive). The chronology is available as a mean value curve, though it it is not known how many samples it was created from. The first release appeared in early 2003 with the declared ambition to release a new version each new year, although the version still available has been there since early 2004. The version from 2004 is unfortunately normalized according to an unknown method. This means that all low frequent variations are removed and that it is problematic to normalize the curve again (which will normally happen when used with for instance CDendro). In the first version (as far as known not available at the museum's web site any longer), it did have much low frequency patterns preserved, and then seemed to work better with at least CDendro.
As only a mean value curve (chronology) is available, and no measurement data, the ways to check the quality of this data is limited. One way to test curves, is by searching for blocks (segments) which may be based on erroneously dated samples. This can be done by testing a huge number of blocks from the chronology towards that same chronology. Then, of course, they will fit towards the positions from where they were taken with corr=1, but if they also fit some where else along the chronology with a corr-value and TTest higher than expected for a false match, we may suspect that erroneously dated samples have been included in the calculation of the chronology. There is a mechanism in CDendro to to do this kind of analysis. The result of this analysis for this chronology (version 2003) is that not any blocks (either with 50 years or 90 years length) gave higher values at best false position than expected. TTest around 5 as highest (using Proportion of last two years growth-normalization) was found which level is in accordance with what may be expected for a curve of high quality.
- westdk.zip. Via WebCite-archive (version from 2004, still present 2009)
- The version from 2003 is available here (WebCite-archive) just in order to make the discussion about it more transparent, and to make it possible to prove datings based on it.
Any use of this curve should be followed by an acknowledgment to the Danish National museum.