fit_hiad - tpcclib 0.8.1 © 2025 by Turku PET Centre

Non-linear fitting of the sum of Hill and Hill derivative function to
the PET time-activity curves (TACs):
f(x) = A * { [n*xt^(n-1)]/[h^n+xt^n] - [n*xt^(2*n-1)]/[h^n+xt^n]^2   
             + [k*xt^n]/[h^n+xt^n] }
, where xt=x-dt and n>=1.
 
Usage: fit_hiad [Options] tacfile [parfile]
 
Options:
 -Hill
     Hill function without the Hill derivative function is used;
     f(x) = (A*xt^n)/(h^n+xt^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.
 -k=<value>
     Parameter k is constrained to given value; setting k to zero causes
     the function to approach zero.
 -n=<value>
     Parameter n (HillSlope) is constrained to the given value;
     n<1 is not allowed.
 -delay=<<value>|mean|median>
     Delay time (dt) is constrained to specified value or to mean or median
     of all TACs.
 -MRL
     Error is returned if MRL check is not passed.
 -res=<Filename>
     Fitted parameters are also written in result file format.
 -svg=<Filename>
     Fitted and measured TACs are plotted in specified SVG file.
 -fit=<Filename>
     Fitted TACs are written in TAC format.
 -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.
 
TAC file must contain at least 2 columns, sample times (x) and
concentrations (y).
Weights can be specified as usual if data is in DFT format.
 
Program writes the fit start and end times, nr of points, WSS,
and parameters of the fitted function to the fit file.
 
See also: fit2dat, fit_sigm, fit_bpr, fit_ppf, fit_exp, fit_ratf
 
Keywords: curve fitting, Hill function