fit_fexp - tpcclib 0.7.8 © 2022 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:
                        -C*x                               
        f(x) = (A-B) * e      + B          , where 0<A<=1 , B>=0 , C>0 
 
Usage: fit_fexp [Options] fractionfile [fitfile]
 
Options:
 -mono
     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.
 -WC
     The last data column contains sample weights.
 -W1
     All weights are set to 1.0 (no weighting)
 -WF
     Less frequent samples are given more weight.
 -ND
     Some fractions are known to exceed 1, not divided by 100.
 -MRL
     Error is returned if MRL check is not passed.
 -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.
 
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).
 
References:
1. Fitting the fractions of parent tracer in plasma.
   http://www.turkupetcentre.net/petanalysis/input_parent_fitting.html
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.
4. http://www.turkupetcentre.net/petanalysis/format_tpc_dft.html
5. http://www.turkupetcentre.net/petanalysis/format_tpc_fit.html
 
See also: fit2dat, metabcor, avgfract, fit_ppf, fit_dexp, tac2svg
 
Keywords: input, plasma, modelling, simulation, metabolite correction