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

This program comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome

to redistribute it under GNU General Public License.

Source codes are available in https://gitlab.utu.fi/vesoik/tpcclib.git.