%%  Kalkan & Gulkan 2004 Prediction Model for Max. Horizontal Component 
%   [InY sigma] = KG04(T,M,R,VS30) returns the natural log value of GM in 
%   unit of "g" and sigma corresponding to specified period, T
%
%   Input Variables:
%	T = Spectral period (s)
%   M = Moment magnitude
%   Rjb = Joyner-Boore fault distance in km
%   VS30 = Average shear-wave velocity in the upper 30 m of crust in m/s
%
%   $Revision: 1.1 $  $Date: 09/15/2010 $
%   Written by Dr. Erol Kalkan (ekalkan@usgs.gov)
%   Reference:  Kalkan E. GŸlkan P. ÒSite-Dependent Spectra Derived from 
%	Ground Motion Records in TurkeyÓ, Earthquake Spectra, Vol. 20, No. 4, 
%	pp. 1111-1138, Nov. 2004

function [InY,sigma] = KG04(T,M,R,VS30);

Coeff = [
0.00	0.393	0.576	-0.107	-0.899	-0.200	1112.000	6.910	0.612
0.10	1.796	0.441	-0.087	-1.023	-0.054	1112	10.07	0.658
0.11	1.627	0.498	-0.086	-1.030	-0.051	1290	10.31	0.643
0.12	1.109	0.721	-0.233	-0.939	-0.215	1452	6.91	0.650
0.13	1.474	0.500	-0.127	-1.070	-0.300	1953	10.00	0.670
0.14	0.987	0.509	-0.114	-1.026	-0.500	1717	9.00	0.620
0.15	1.530	0.511	-0.127	-1.070	-0.300	1953	10.00	0.623
0.16	1.471	0.517	-0.125	-1.052	-0.298	1954	9.59	0.634
0.17	1.500	0.530	-0.115	-1.060	-0.297	1955	9.65	0.651
0.18	1.496	0.547	-0.115	-1.060	-0.301	1957	9.40	0.646
0.19	1.468	0.575	-0.108	-1.055	-0.302	1958	9.23	0.657
0.20	1.419	0.597	-0.097	-1.050	-0.303	1959	8.96	0.671
0.22	0.989	0.628	-0.118	-0.951	-0.301	1959	6.04	0.683
0.24	0.736	0.654	-0.113	-0.892	-0.302	1960	5.16	0.680
0.26	0.604	0.696	-0.109	-0.860	-0.305	1961	4.70	0.682
0.28	0.727	0.733	-0.127	-0.891	-0.303	1963	5.74	0.674
0.30	0.799	0.751	-0.148	-0.909	-0.297	1964	6.49	0.720
0.32	0.749	0.744	-0.161	-0.897	-0.300	1954	7.18	0.714
0.34	0.798	0.741	-0.154	-0.891	-0.266	1968	8.10	0.720
0.36	0.589	0.752	-0.143	-0.867	-0.300	2100	7.90	0.650
0.38	0.490	0.763	-0.138	-0.852	-0.300	2103	8.00	0.779
0.40	0.530	0.775	-0.147	-0.855	-0.264	2104	8.32	0.772
0.42	0.353	0.784	-0.150	-0.816	-0.267	2104	7.69	0.812
0.44	0.053	0.782	-0.132	-0.756	-0.268	2103	7.00	0.790
0.46	0.049	0.780	-0.157	-0.747	-0.290	2059	7.30	0.781
0.48	-0.170	0.796	-0.153	-0.704	-0.275	2060	6.32	0.789
0.50	-0.146	0.828	-0.161	-0.710	-0.274	2064	6.22	0.762
0.55	-0.306	0.866	-0.156	-0.702	-0.292	2071	5.81	0.808
0.60	-0.383	0.881	-0.179	-0.697	-0.303	2075	6.13	0.834
0.65	-0.491	0.896	-0.182	-0.696	-0.300	2100	5.80	0.845
0.70	-0.576	0.914	-0.190	-0.681	-0.301	2102	5.70	0.840
0.75	-0.648	0.933	-0.185	-0.676	-0.300	2104	5.90	0.828
0.80	-0.713	0.968	-0.183	-0.676	-0.301	2090	5.89	0.839
0.85	-0.567	0.986	-0.214	-0.695	-0.333	1432	6.27	0.825
0.90	-0.522	1.019	-0.225	-0.708	-0.313	1431	6.69	0.826
0.95	-0.610	1.050	-0.229	-0.697	-0.303	1431	6.89	0.841
1.00	-0.662	1.070	-0.250	-0.696	-0.305	1405	6.89	0.874
1.10	-1.330	1.089	-0.255	-0.684	-0.500	2103	7.00	0.851
1.20	-1.370	1.120	-0.267	-0.690	-0.498	2103	6.64	0.841
1.30	-1.474	1.155	-0.269	-0.696	-0.496	2103	6.00	0.856
1.40	-1.665	1.170	-0.258	-0.674	-0.500	2104	5.44	0.845
1.50	-1.790	1.183	-0.262	-0.665	-0.501	2104	5.57	0.840
1.60	-1.889	1.189	-0.265	-0.662	-0.503	2102	5.50	0.834
1.70	-1.968	1.200	-0.272	-0.664	-0.502	2101	5.30	0.828
1.80	-2.037	1.210	-0.284	-0.666	-0.505	2098	5.10	0.849
1.90	-1.970	1.210	-0.295	-0.675	-0.501	1713	5.00	0.855
2.00	-2.110	1.200	-0.300	-0.663	-0.499	1794	4.86	0.878
];

b1 = interp1(Coeff(:,1),Coeff(:,2),T);  
b2 = interp1(Coeff(:,1),Coeff(:,3),T);
b3 = interp1(Coeff(:,1),Coeff(:,4),T);
b5 = interp1(Coeff(:,1),Coeff(:,5),T);
bV = interp1(Coeff(:,1),Coeff(:,6),T);
VA = interp1(Coeff(:,1),Coeff(:,7),T);
h = interp1(Coeff(:,1),Coeff(:,8),T);
 
sigma = interp1(Coeff(:,1),Coeff(:,9),T);

r = sqrt(R^2 + h^2);

InY = b1 + b2 * (M - 6) + b3 * (M - 6)^2 + b5 * log(r) + bV * log (VS30 / VA);
  
return