CalcWidthSum - Calculates the total ring widths for a group of CooRecorder .pos files.

Intended usage: To calculate the sum of measured bark widths for study of basal area increments for a BIG number of separately measured tree ring samples.

When the number of such sample files is VERY high it would be difficult to select the files one by one. By using "multiselect" within Windows, things are made much easier: Click on the first file, then shift-click on the last file in the list and all intermediate files are selected in one operation! You can even ctrl-click on an already selected file to unselect it. Or ctrl-click again to reselect.

The output file of CalcWidthSum contains rows where each row contains the filename and the sum of the ring widths found within that .pos file. The output file can be imported into e.g. MS Excel for further processing together with other tree ring data related to these measurements. The program can certainly be used also for other applications.

.pos files are created with the CooRecorder program which is available at

An example of a CooRecorder-created .pos file which can be read with CalcWidthSum:
#DENDRO (Cybis Dendro program compatible format) Coordinate file written as I:\Chronologies\6\6_1 bark.pos
#Imagefile 6_1.JPG
#DPI 1600.0
#All coordinates in millimeters (mm)
246.936,8.906 262.779,21.272

The CalcWidthSum.exe program may be freely distributed. It is written by Lars-Åke Larsson,, after a request and an idea from Liam Cavin at The University of Stirling.

Download link: CalcWidthSum.exe After saving the program, double-click it to make it start.


Hi Lars-Ake,

I have a problem with some .pos files that I have created, and I wondered if you would be able to give me some advice. I have a dataset of approximately 3600 cores, which I wanted to analyse using basal area increment. I measured the cores, and I have created chronologies using CDendro. One thing occurred to me though – when using ring widths and stem diameter to calculate basal area increment, I should take into account the thickness of the bark. So, I went back to my cores and used CooRecorder to measure the bark, as a separate series of .pos files. I thought I could then import them into CDendro, and create a .rwl file, thus giving me the bark measurements in a format that I could then look at in R. My problem is that the each bark file is a very short series, and that CDendro doesn’t seem to like dealing with .pos files which consist of just a few coordinates. ...

I’m aware that I am sort of abusing the programme – i.e. trying to make it do something that it was not designed for. However, do you know of any way that I can use my bark measurements? Essentially what I want is to get a sum length of measurements for each .pos file. Your webpage says that you use CooRecorder for measurements on bees, so I’m hoping that you have a way of using measurements that are not annual ring series.

To clarify:

  • Each original .pos file referred to an image with 2 cores from one single tree.
  • Therefore, each .pos file consists of a short series of widths covering 2 pieces of bark from 2 cores from the same tree.
  • The "more than one point per line" data picking mode was used to jump from one core’s bark to the next, and crack marker used to deal with broken/fragmented bark.
  • I need a sum of all widths in each .pos file.

Best wishes,
Liam Cavin

December 21 2012.