fit_pbr - tpcclib 0.8.0 © 2023 by Turku PET Centre

Non-linear fitting of a function to sampled plasma-to-blood ratio (PBR) data.
Plasma-to-blood ratio is calculated from RBC-to-plasma ratio (RPC) as
and RBC-to-plasma ratio is modelled with function 1 (SRC)
  RPC(t)=p1*t*exp(-p2*t) + p3*p1*(1-exp(-p2*t)*(1+p2*t))/(p2*p2)
function 2 (FM2)
  RPC(t)=(p1*t-p3-p5)*exp(-p2*t) + p3*exp(-p4*t) + p5*exp(-p6*t)
function 3 (RF)
  RPC(t)=(p1*t + p3*t^2 + p5*t^3) / (1 + p2*t + p4*t^2 + p6*t^3)
or function 4 (HILL)
  RPC(t)=(p1*t^p2)/(t^p2 + p3)
Usage: fit_pbr [Options] datafile [parfile]
     Constrain haematocrit to specified value; fitted by default.
     Use function 1 (SCR, default), function 2 (FM2), function 3 (RF), or
     function 4 (HILL).
     Sum-of-squares (OLS) is minimized by default, but optionally
     sum of absolute deviations (LAD) can be selected.
     All weights are set to 1.0 (no weighting); by default, weights in
     data file are used, if available.
     Weight by sampling interval.
     Parameter k is constrained to given value.
     Specify the constraints for function parameters;
     This file with default values can be created by giving this option
     as the only command-line argument to this program.
     Without file name the default values are printed on screen.
     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.
Datafile must contain at least 2 columns, sample times and ratios,
possibly also weights as last column.
     fit_pbr -svg=ia765pbrat.svg ia765pb.rat
See also: fit_bpr, tacinv, tacblend, b2rbc, bpr2cpr, fit_sigm, fit_hiad
Keywords: curve fitting, input, blood, plasma, modelling, simulation