Fityk Changelog

New in version 1.2.1

November 8th, 2012
  • added commands '=' and 'exec=' - shorthands 'lua return' and 'lua F:execute'
  • API: default dataset in a few functions changed from @0 to the currently used
  • GUI: new dialog GUI > Configure > Default Directories
  • a few tweaks and fixes related to printing, and other bug fixes

New in version 1.2.0 (May 29th, 2012)

  • added fitting method "mpfit" -- wrapper around MINPACK-1 based MPFIT library (
  • changed public API of libfityk; now cfityk uses only public API
  • added C API and Ruby and Java bindings to libfityk
  • enhanced Python API and added Python equivalent of cfityk (samples/
  • CLI: cfityk can be built with libedit (but it works better with readline)
  • in scripts, backslash (\) at the end of line means line continuation * bug fixes, as usually

New in version 1.1.1 (October 3rd, 2011)

  • option exit_on_warning=0/1 was replaced with on_error=stop/exit; new option on_error=nothing allows to ignore errors in script.
  • current working directory can be changed using new option `cwd'
  • GUI: a new dialog for Model > Export Formula
  • minor bug fixes

New in version 1.1.0 (July 20th, 2011)

  • embedded Lua (lightweight programming language)
  • syntax changes and enhancements in dataset transformations (@n = ...); example: "@0 = @0 - 0.23 * @1" removes (background) @1 with y's scaled by factor 0.23 from dataset @0; if @0 and @1 have different x's, linear interpolation is used.
  • added calculation of Polyline derivatives, what enables weighted least squares approximation by broken lines
  • gzipped fit files can be read directly (extension .fit.gz or .fityk.gz)
  • new option max_fitting_time -- stopping criterium based on elapsed time
  • GUI: mouse wheel and mouse extra buttons can be used to zoom in/out
  • Mac GUI: added Session > New Window that opens new window (open -n
  • GUI: added optional, configurable description in the corner of the main plot
  • GUI: Session > Copy to Clipboard works differently and on all platforms now
  • GUI: enhanced file dialogs: Data > Quick Load and Session > Save as Image
  • fixed all reported bugs

New in version 1.0.2 (June 10th, 2011)

  • changed Data > Load File dialog
  • fixed a few minor problems and a major one (GUI not working on OSX 10.5)

New in version 1.0.1 (April 1st, 2011)

  • corrected calculation of Exponentially Modified Gaussian
  • added calculation of confidence intervals
  • GUI: anti-aliasing (can be switched off in menu GUI > Anti-aliasing)
  • added (experimental) option guess_uses_weights that changes peak "guessing"
  • minor changes in the GUI and one bug fix in the powder diffraction add-on

New in version 0.9.7 (February 9th, 2011)

  • bug fixes: UDFs (user-defined functions) did not work in ver. 0.9.5-6, a few fixes in the powder diffraction add-on and in other places
  • data operations: added aggregate functions argmin, argmax and count
  • GUI: redesigned the Data > Export dialog

New in version 0.9.6 (January 27th, 2011)

  • A few bug fixes

New in version 0.9.5 (January 25th, 2011)

  • libfityk: the parser has been completely rewritten and the syntax was slightly changed:
  • major changes in the `info' command; two new commands, `print' and `debug', partially took over some functionality of the old `info'
  • "commands" replaced by "set"/"exec"
  • "dump" replaced by "info state"
  • values of the fitting_method setting changed to lower case
  • "set @0.title = ..." replaced with "@0: title = ..."
  • settings: removed formula_export_style, guess_at_center_pm and can_cancel_guess, changed autoplot and verbosity, added logfile, log_full, fit_replot, info_numeric_format renamed to numeric_format, data_default_sigma to default_sigma, cut_function_level to function_cutoff, variable_domain_percent to domain_percent
  • in "define ... where param=expr" expr is substituted in brackets now
  • added syntax: delete file 'filename'
  • "guess": changed argument order
  • F.param = $variable -> F[*].param = $variable. See the wiki for details (there is a tool that upgrades fityk scripts).
  • new website address ( and new code repository (GitHub)
  • GUI: simplified two dialogs: Edit Script and Definition Manager
  • error in script stops the script