I use a program called COFECHA to help crossdate trees. COFECHA uses some old school formats developed for punch-cards. Excel, which I used to make changes to ring widths, does not like these formats. There are lots of programs for changing formats, but it’s all a bit confusing.

Many dendrochronology programs produce and use Compact/Precision formats. When crossdating trees with the program COFECHA, it is often useful to convert Compact/Precision formats to formats recognized by spreadsheet programs like Excel and then convert back to Compact/Precision formats to run through COFECHA. So for any other confused dendrochronologists out there, here’s a method that works for me.

Compact/Precision format looks like this when you open it with notepad:

ira 11946 170 200 216 755

ira 11950 529 332 405 342 384 760 647 363 556 466

ira 11960 288 431 490 124 827 282 319 248 441 1082

ira 11970 1601 498 992 1407 850 1053 1356 951 1145 1621

ira 11980 1756 1381 1397 1626 1868 2739 2447 2250 1684 1942

ira 11990 1401 1390 861 1389 1158 1421 1454 1040 -9999

Sometimes the numbers seem to run together, but each line will start with a series identifier and each series will end with -9999.

Convert file from Compact/Precision to tab delimited .txt file with program YUX. Open .txt file with Excel and make necessary changes, being sure to save as a tab delimited .txt file. Convert to Compact/Precision format with program CASE, being sure to save the new file as a .rwl. COFECHA should be able to read this file.

If you get COFECHA output that only includes the title or part of the desired output, try playing around with the print options in COFECHA.  If COFECHA produces a completely empty output file, try copying and pasting the information from your .rwl file into an existing .rwl file and saving it as a new .rwl file.

All programs can be downloaded from the Ultimate Tree Ring Web Pages run by Henri Grissino-Mayer.