The following contain the revised PRECON (version 5.17c) PKZIP files:
These are all new files for the revised PRECON, Version 5.17c. This corrects a bug in Version 5.17a and 5.17b that caused a runtime error when the climatic file started 1 or 2 years after the chronology file. The GBA program can be called at any time in the 32 bit version using the ALT G, so it is not necessary to use Menu Option 9. The boot strap program will run up to 99999 iterations if anyone ever wants to run that many. I recommend running at least 30 iterations for experimenting with different models. You may want to run more iterations for final publications. Joel Guiot tells me that there is little significant change after 50 iterations although others have recommended up to 1000.
The following are additional PKZIP files provided in the original disk and have not changed:
This new version of PRECON 5.17c A) corrects some bugs in Versions 5.0 through 5.17b involving reading of the chronology file, B) allows you to assign longer paths and file names, C) enables the analysis of earlywood and latewood data, and D) allows a more complete analysis of data from the Southern Hemisphere as well as a few other conveniences.
If you enter E or L in the earlywood or latewood option, then the program assumes that the first file read is either earlywood or latewood and will prompt you for a second file that will be the latewood of the previous year or earlywood of the current year. In the analysis of the response function, the three prior growth values for earlywood will be the late- wood and earlywood of the preceding year and latewood two years previously. For latewood the prior growth values will be the earlywood of the current year and the latewood and early- wood of the preceding year.
If you choose the option for Southern Hemisphere data, the climatic data are read, moved backward in time by 6 months, and rewritten in a file with the .t_t or .p_p extent. This is the same as beginning the calendar year in July instead of January so Month 1 in the Southern Hemisphere year will be July, month 2, August and so forth. The program simply displaces the climatic data so you can include values for the years prior to growth comparable to the Northern Hemisphere. The year of growth follows the convention for Southern Hemisphere chronology data in that the year assigned to the ring-width index is the year in which growth begins. There is no longer any need to change the date to run PRECON and you can include more months extending the coverage to the end of the growing season. Those of you who have data using these two options, please try the options out and let me know if you encounter any problems.
Just as in the earlier version of PRECONK (2.1 - 5.1) the program can generate input for the KALMAN FILTER PROGRAM written by Ed Cook, which I have revised to use input from PRECONK. The Kalman filter file was not included in the distribution disk and if you know how and want to use it you must obtain it here. All EXE files will run under Windows 95.
For those who are registered owners of the full program, if you encounter difficulties in the future, please do me a great favour by sending as much information as you can on the problem, including the *.out file generated by the problem, and I will try to correct the code, recompile it and send you a new free updated version as promptly as possible.
Sincerely, Harold C. Fritts
Download the PRECO517.ZIParchive which contains all information needed to upgrade old versions and the revised 32 bit program and the PREADME file.
Download the KALMAN.ZIParchive which contains the Kalman filter program..
Download the NEWPRDAT.ZIP file. archive with the manual.
If you want to try the program, even without graphics, also downloadPRCONCLD.ZIP and PRCONPCN.ZIP.
Prepared by Harold C. Fritts hfritts@LTRR.arizona.edu -- Last updated March 29, 2000