On using Skeleton plots for crossdating 

Skeleton plotting is available in CDendro when any of the two Skeleton alternatives is selected as "Check to display" in the Settings/Options for normalization... window. 

Skeleton plots were drawn by hand on graph paper. Each vertical line on the graph paper correponds to one ring of the sample. The ring widths are inspected with a magnifying glass and vertical lines of various height are drawn for those lines which are narrow. Especially wide rings are marked with a "b" (broad). "Normal rings" are left undrawn. If you draw your plots on strips of graph paper, these strips can be horizontally shifted relative to each other so you can find where the plots match each other. 
Then check the appropriate checkbox as shown above and click OK. 


(The slider (trackbar) of the "Settings/Plotting window settings/Set relative height of ring width curves" has also been somewhat adjusted to make the ring width curve higher.) 
You can remove the growth curves by unchecking the checkboxes shown at (1) above. A statistical Chi Square value for the current match between sample and reference is also available, as shown at (2) above. 
If we only use the Skeleton Chi2 values as the selection criteria when dating 80 year long blocks of Scots pine grown here in Saltsjöbaden towards a reference curve from the nearby island of Nämdö, we will only have some 30% of our blocks with Chi2 values above 15 though with one third of them with a wrong dating. 


A normal correlation coefficient can be calculated for two such curves (red and blue) laying over each other. 


