fit_tac 0.1.0 © 2008 by Turku PET Centre
Non-linear fitting of an exponential sum function to PET tissue
time-activity curves (TACs).
Function:
when t<=tau: y(t) = 0
when t>tau: y(t) = (p1*(t-tau)-p3)*exp(p2*(t-tau)) + p3*exp(p4*(t-tau))
+(p5*(t-tau)-p7)*exp(p6*(t-tau)) + p7*exp(p8*(t-tau))
Usage: fit_tac [Options] <Datafile> <FIT file>
Options:
-function=<MFENG|MLUNQ|LUNQ|MGVAR|HGVAR|HMGVA|WEIB>
Select the function; by default MFENG (above)
-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
-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, p5, p6, p7, p8, tau) of the fitted function
to the FIT file (2).
Example 1: Fit function to plasma TAC and compute fitted curve
between 0 and 60 min at 0.1 min intervals:
fit_tac p455ap.kbq p455ap.fit
fit2dat -c=0,60,0.1 p455ap.fit p455ap_new.kbq
Example 2: Fit function to plasma TAC and plot fitted and measured TACs
in SVG format:
fit_tac -svg=p455apfit.svg p455ap.kbq p455ap.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_sinf,
fit_exp,
fit_ratf,
fit_hiad
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.