## This function will solve the Generalized Power Law (GPL)
 ## and calculate (estimate) the parameters D0,D1 and m 
 ## in the GPL model D(t) = D0 + D1*t^m
 ##    note t = reduced time

## Author: Steph Bredenhann <address@hidden>
## Created: 2020-03-14

function [ GPL_Y ] = fn_BBR_GPL( x, D, t);

##fprintf('fn_GPL: Entering function fn_GPL_RMSE: \n');
##fprintf('   GPL_D0 = %9.7f \n',x(1));
##fprintf('   GPL_D1 = %9.7f \n',x(2));
##fprintf('   GPL_m  = %9.7f \n',x(3));

##  n_max = length(D);  
##  fprintf('fn_GPL: n_max = %7.1f \n',n_max);

  D0 = x(1);
  D1 = x(2);
  m  = x(3);
  
  Dcalc = fn_GPL_model(D0, D1, m, t);
  GPL_Y = Dcalc - D;
  
end