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