residuals method
Calculates the residuals from the y-values and the model params
r_i = 1/w_i * (y_i - model(x_i, params))
Implementation
List<double> residuals(List<double> params) {
List<double> resid = List<double>(xvals.length);
for (int i = 0; i < xvals.length; i++) {
double val = (1 / weights[i]) * (yvals[i] - model(xvals[i], params));
resid[i] = val;
}
return resid;
}