WestDK

WestDK. Chronology for western part of Denmark; Jylland and Fyn, AD 200-1986, by The National Museum of Denmark in Copenhagen (WebCite). The chronology is available as a mean curve, and it it is not known how many samples is behind. The first release did appear in early 2003, and the ambition was to release a new version each new year, although the version still available has been there sins early 2004. The version from 2004 is unfortunately normalized according to an unknown method. This means that all low frequent variations is removed and that it is problematic to normalize again (which will normally happen when used with for instance CDendro). In the first version (as far as known, not available on the web any more), it did have much low frequency pattern preserved, and seems to work better with at least CDendro.

Quality

As only a mean curve (chronology) is available, and no measurement data, the ways to check the quality of this data is restricted. One way to test curves, is by searching for blocks which may be based on erroneously dated samples. This can be done by testing a huge number of blocks from the chronology and test them towards the same chronology. Than, of course, they will fit towards the position where they was 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, one 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 two last years-normalization, was found and that level is in accordance with what may be expected for a curve of high quality.

Download

• westdk.zip. Via WebCite (version from 2004, still present 2009)