var4tac - tpcclib 0.8.0 © 2023 by Turku PET Centre

Program for adding Gaussian noise to dynamic PET time-activity curve (TAC)
or TACs using equation
  TAC_noisy(t) = TAC(t) + (CV/100)*TAC(t)*G(0,1) ,
G(0,1) is a pseudo random number from a Gaussian distribution
with zero mean and SD of one.
 
Usage: var4tac [Options] tacfile CV outputfile 
 
Options:
 -minsd=<Percentage of maximal SD>
     Based on CV only the time frames with little or no activity would have
     very little or no noise. With this option the noise level (SD) in all
     time frames will be at least the given percentage of the maximal SD
     of all time frames and TACs.
 -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.
 
Frame durations are not used, even if available in the TAC file.
If TAC file contains weight column, then the specified amount of variance is
added to frames with weight=1, and higher or lower variance to those
frames with lower or higher weight.
 
Example:
     var4tac simulated.tac 10 noisy.tac
 
See also: svar4tac, fvar4tac, sim_3tcm, tacweigh, tacadd, avgttac
 
Keywords: TAC, simulation, noise