/*------------------------------------------------------------------*/ double getInitialCausalCoefficientMirrorOnBounds(double[] c, double z, double tolerance) { double z1 = z, zn = Math.pow(z, c.length - 1); double sum = c[0] + zn * c[c.length - 1]; int horizon = c.length; if (0.0 < tolerance) { horizon = 2 + (int) (Math.log(tolerance) / Math.log(Math.abs(z))); horizon = (horizon < c.length) ? (horizon) : (c.length); } zn = zn * zn; for (int n = 1; (n < (horizon - 1)); n++) { zn = zn / z; sum = sum + (z1 + zn) * c[n]; z1 = z1 * z; } return (sum / (1.0 - Math.pow(z, 2 * c.length - 2))); } /* end getInitialCausalCoefficientMirrorOnBounds */