fit_dexp - tpcclib 0.7.3 © 2019 by Turku PET Centre

Non-linear fitting of the sum of 1-5 exponential functions to decaying
time-activity curve (TAC).
 
Function:
 
  f(x) = a1*exp(k1*x) + a2*exp(k2*x) + a3*exp(k3*x) + ...
 
, where a's > 0 and k's < 0.
 
Usage: fit_dexp [Options] tacfile parfile
 
Options:
 -5 | -4 | -3 | -2 | -1
     Fit to sum of specified number of exponential functions; by default
     determined automatically.
 -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.
 -svg=<Filename>
     Fitted and measured TACs are plotted in specified SVG file.
 -nr=<value>
     Number of basis functions, used in determination of initial parameter
     estimates and number of exponentials for nonlinear fitting;
     default is 100.
 -peak | -peak1
     Fit is started only at the TAC peak, or at the next sample after peak.
 -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.
 
If TAC file contains more than one TAC, only the first is used.
Function parameters are written in fit format.
 
See also: fit_exp, fit_fexp, fit_ratf, fit2dat, extrapol, paucinf, tacln
 
Keywords: TAC, curve fitting, extrapolation