fit_fexp - tpcclib 0.8.0 © 2023 by Turku PET Centre

Fits the following exponential function to plasma parent (unchanged) tracer
fraction curve, where fractions are between 0 and 1 (1,2).
                             -B*x  -C*x                               
        f(x) = 1 - A * (2 - e    -e    )   , where 0<A<=1 , B>0 , C>0 
Optionally a monoexponential function, where fractions are between A and B,
can be applied instead:
        f(x) = (A-B) * e      + B          , where 0<A<=1 , B>=0 , C>0 
Usage: fit_fexp [Options] fractionfile [fitfile]
     Use monoexponential function.
 -a=<value> or -a=zero
     Parent fraction at time zero (A) is fixed to given value, or to
     the value of zero sample, if available.
     Applicable only with monoexponential function.
     The last data column contains sample weights.
     All weights are set to 1.0 (no weighting)
     Less frequent samples are given more weight.
     Some fractions are known to exceed 1, not divided by 100.
     Error is returned if MRL check is not passed.
     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.
Fraction datafile must contain two columns, sample times (min) and fractions
of parent tracer. Weights can be specified as specified in DFT format (4);
any additional columns are ignored.
Lines that start with a '#' are not read from the datafile.
Program writes the fit start and end times, nr of points, WSS/n,
and parameters of the fitted function to the FIT file (5).
1. Fitting the fractions of parent tracer in plasma.
2. Kropholler MA, Boellaard R, Schuitemaker A, van Berckel BNM, Luurtsema G,
   Windhorst AD, Lammertsma AA. Development of a tracer kinetic plasma input
   model for (R)-[11C]PK11195 brain studies. J Cereb Blood Flow Metab. 2005;
   25(7): 842-851.
See also: fit2dat, metabcor, avgfract, fit_ppf, fit_dexp, tac2svg
Keywords: input, plasma, modelling, simulation, metabolite correction