## fit_wcdf - tpcclib 0.7.8 © 2022 by Turku PET Centre

Non-linear fitting of the Weibull CDF and Weibull PDF sum function to PET
time-activity curves (TACs).
Function:
when x<=dT, f(x) = 0
when x>dT, f(x) = A * (n/B) * ((x-dT)/B)^(n-1) * exp(-((x-dT)/B)^n) +
k * A * (1-exp(-((x-dT)/B)^n))
, where A>=0, B>0, n>0 (usually n>1), k>=0, and dT>=0.
Usage: fit_wcdf [Options] tacfile [parfile]
Options:
-CDF
WCDF function without WPDF (derivative of WCDF) is fitted:
when x>dT, f(x) = A * (1-exp(-((x-dT)/B)^n))
-w1
All weights are set to 1.0 (no weighting); by default, weights in
data file are used, if available.
-wf
Weight by sampling interval.
-lim[=<filename>]
Specify the constraints for function parameters;
This file with default values can be created by giving this option
as the only command-line argument to this program.
Without file name the default values are printed on screen.
-delay=<time>
Delay time (dT) is constrained to specified value (>=0).
-k=<value>
Parameter k is constrained to given value; setting k to zero causes
the function to approach zero.
-svg=<Filename>
Fitted and measured TACs are plotted in specified SVG file.
-h, --help
Display usage information on standard output and exit.
-v, --version
Display version and compile information on standard output and exit.
-d[n], --debug[=n], --verbose[=n]
Set the level (n) of debugging messages and listings.
-q, --quiet
Suppress displaying normal results on standard output.
-s, --silent
Suppress displaying anything except errors.
See also: fit_sinf, fit_feng, fit_ratf, fit2dat, extrapol
Keywords: TAC, curve fitting