********************************************************************* Comprehensive list of improvements and modifications to the GasFit System ********************************************************************* Version 4.x =========== GasFit 4 is a major upgrade of both the program and the fitting script, and it may require (re)registration. Every run now produces a complete HTML report, all of the charts were rebuilt, several fitting and reporting defects were corrected, and a run starts and finishes faster. GasFit remains a front end to R: the modeling is done by the GasFit R script, and R (free of charge) must be installed from http://www.r-project.org. 4.0.9749.18372 (2026-09-10) -------------- (1) A run no longer stops at random with "cannot open the connection". The progress display was locking the log file for an instant each time it refreshed, while the fitting script writes to that file on every log line, and a collision ended the run with status code 30 at whichever model happened to be running. The program now reads the log without blocking the script. (2) The fitting script (now 4.2.0) retries a log line that cannot be written and then drops it rather than aborting the run, so any other program reading the file, such as an antivirus scan, cannot end a run either. Results are unchanged. (3) While the log is momentarily unreadable, the progress box keeps its last contents instead of flashing an error message. 4.0.9738.26351 (2026-08-30) -------------- (1) A new start-up screen. The card now names who the copy is licensed to, with the license and register numbers and the date the license was issued, beside the machine it is running on, the notice, and the status of the start-up checks. An evaluation copy says so and shows the evaluations remaining. The screen matches the one used by RNS and SRNS, so the programs on this desk now open alike. (2) The licensed-to block now shows the date the license was ISSUED. It had shown the installation date instead, which names the wrong day for any copy registered after it was installed. Nothing about the registration itself changed, and no code needs to be re-entered. (3) The notice on the start-up screen now carries the copyright line as well as the disclaimer, both read from the program itself. 4.0.9737.21556 (2026-08-29) -------------- (1) Standardized the spelling throughout to American English, in both the GasFit program and the R script. 4.0.9736.33246 (2026-08-28) -------------- (1) The third-party interface controls and the shared registration and web update libraries were updated to their current releases and the program was rebuilt against them. This is an internal change with no effect on how GasFit is used. 4.0.9725.26764 (2026-08-17) -------------- (1) GasFit now writes a complete HTML report of every run (report.html), and can open it in your browser automatically when the run finishes. (2) All of the charts were rebuilt for clarity and readability, and are now numbered so that the results folder sorts into reading order. If you have spreadsheets, documents or scripts that pick up chart files by name, they need to be pointed at the new names. (3) Fixed a defect that could end a run outright, with no message and no results, which looked like GasFit had frozen. (4) Fixed the model error charts, which ranked the models in exactly reverse order, so the best model drew the longest bar. (5) Fixed the summary statistics and the distribution charts, which reported the regression sum of squares in place of the error sum of squares, and the total sum of squares in place of the convergence time. (6) The Iterations column of the result tables is no longer empty. (7) Two-pool GnG1 fits now converge, where they had never converged on any profile, and the one-pool case that cannot be fitted is skipped with the reason recorded in the log rather than reported as a failure. (8) The Richards model fits about 40 times faster, and every run now starts fitting about 9 seconds sooner. (9) Added two new result files, Model Fit Statistics.csv and Fitted Values.csv, and a model name column in Summary Table.csv. The existing result files are unchanged, so existing spreadsheets keep working. (10) Create parms now writes to the parameter file you selected rather than to the working folder, and the file it creates can be used as is. (11) Projects (.GFF) now save the Levenberg-Marquardt fitting method and the plot resolution, and a leading space in the profile boxes no longer stops the run before it starts. (12) Fixed the interface freezing while R was running, and when a run was stopped part way through. (13) Improved the search for R engines, which now orders the installations by real version number rather than as text. (14) A run that fails now reports the actual R error and a status code instead of ending in silence. (15) Revised the Splash Screen, the About box and the update process. Opening the About box no longer consumes one of the evaluation runs. Version 3.x and earlier ======================= (1) Fixed date for registration. (2) Fixed interface. (3) Revised Excel template (v41). (4) Improved search for R engines in the AppData folder and the root of the C: drive. (5) Added bypass registration. (6) Updated web downloader.