fit_gvar 1.2.1 © 2003-2008 by Turku PET Centre

Non-linear fitting of Gamma variate function with time delay term to plasma and tissue time-activity curves (TACs) using iTGO. Function: | 0 , t < p4 f(t) = | | p1*((t-p4)^p2)*exp(-(t-p4)/p3) , t >= p4 Usage: fit_gvar [Options] <Data file> <FIT file> Options: -stoptime=<Fit end time> All data with sample time > stoptime is excluded from the fit. -thr=<Threshold%> Any time points that are less than Threshold% of the maximum after the peak of the curves is not used in the fit. Hint: try to set threshold close to 100, e.g. 99%, to get a good estimate of tracer appearance time. -auto Automatically sets the fit range from 0 to peak + at least one sample more, until WSS/n gets worse. -wf Weight by sampling interval -fast or -safe Speed up the fitting but increase the chance of failure, or increase the reliability at the cost of computing time -fit=<Filename> Fitted TACs are written in DFT format (1) -svg=<Filename> Fitted and measured TACs are plotted in specified SVG file -h or --help Print this message and exit --version or --build Print software build information and exit --silent Program works silently, printing only error and warning messages --verbose Program prints lots of information about what it is doing Datafile can be any DFT file (1) which can include weights. Program writes the fit start and end times, nr of points, WSS/n, and parameters (p1, p2, p3, p4) of the fitted function to the FIT file (2). Example: fit_gvar -t=40 -svg=t876gvar.svg t876.dat t876gvar.fit References: 1. http://www.turkupetcentre.net/analysis/doc/format_dft.html 2. http://www.turkupetcentre.net/analysis/doc/format_fit.html See also: fit2dat, fit_feng, fit_exp, dftrmbkg Keywords: DFT, input, modelling, simulation This program comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under GNU General Public License.