Estimate Distance and Rings to Pith

Last update 5 March 2014.
CooRecorder has a tool to measure the "distance to pith". The distance is saved in millimetres as a special comment within the .pos file and is picked up by CDendro as a property. There is also a tool to estimate the number of rings to pith. From version 7.8 of 3 March 2014 there is also a mechanism to export distance to pith information from a CDendro collection over to the dplR program package.
You first need to get enough space around your image so that you can position your cursor at a point corresponding to where the pith should be. So for this example above, it is best to click Cancel, then check the "Image pos" checkbox as described below and position the image properly. Then it is time to click the Distance to pith icon again and then the "OK, define now" button shown in the picture above.
You first need to get enough space around your image so that you can position your cursor at a point corresponding to where the pith should be. To make this, see that you use the Zoom-Out tool (Ctrl-Z, "demagnifying glass" ) to make your image small enough. Usually it is not to advantage to have the picture centred in the middle of the picture frame as by default. In this case it would be better to have it at the top of the frame so that there is free space below the picture. To do this, check the "Image pos" checkbox near to the top right corner of the screen. With the scrollbar(s) then made visible below that checkbox you can now move your image to a suitable position as in the example above.

Then click the "Set distance to pith" icon and then the "OK, define now" button and position the cursor where the pith should have been and click at that point.

You may now choose what you consider as a reasonable number of "years to pith"!
The distance is saved in millimetres as a special comment within the .pos file and is picked up by CDendro as a property. Also the YearsToPith information is saved as a property within the .pos file.

The pith coordinates are also saved as a property when Distance to pith is set. A flag (property) "CalcRadius" can be set when the Distance To Pith is set to indicate if the core is in one bit so that the full radius (or successively grown radii) may be correctly calculated. The radius to the outermost ring is then calculated and saved as a property.
(This paragraph is valid from version 7.8 of 3 March 2014 and later.)

Exporting distance to pith to dplR from CDendro

Valid from version 7.8 of 3 March 2014.
After a request by Olivier Bouriaud, there is now a new mechanism to export distance to pith data to the dplR program package.

If you register distance to pith as described above for a group of .pos-files, these files can be added into a collection in CDendro and synchronized. By using the new command "Collections/Save current collection/...as STRIPPED Heidelberg (*.fh) with DistToPith .txt file for export to dplR" you can export the ring width data in a Heidelberg format that is readable to a dplR function together with a .txt file containing DistanceToPith values. Please note that if the distance to pith value is missing for a member of the collection, then the value will anyhow be exported but then as zero (0).



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