function [ n_data, a, x, fx ] = gamma_inc_values ( n_data ) %*****************************************************************************80 % %% GAMMA_INC_VALUES returns some values of the incomplete Gamma function. % % Discussion: % % The (normalized) incomplete Gamma function P(A,X) is defined as: % % PN(A,X) = 1/Gamma(A) * Integral ( 0 <= T <= X ) T**(A-1) * exp(-T) dT. % % With this definition, for all A and X, % % 0 <= PN(A,X) <= 1 % % and % % PN(A,INFINITY) = 1.0 % % In Mathematica, the function can be evaluated by: % % 1 - GammaRegularized[A,X] % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 10 November 2004 % % Author: % % John Burkardt % % Reference: % % Milton Abramowitz and Irene Stegun, % Handbook of Mathematical Functions, % US Department of Commerce, 1964. % % Stephen Wolfram, % The Mathematica Book, % Fourth Edition, % Wolfram Media / Cambridge University Press, 1999. % % Parameters: % % Input/output, integer N_DATA. The user sets N_DATA to 0 before the % first call. On each call, the routine increments N_DATA by 1, and % returns the corresponding data; when there is no more data, the % output value of N_DATA will be 0 again. % % Output, real A, the parameter of the function. % % Output, real X, the argument of the function. % % Output, real FX, the value of the function. % n_max = 20; a_vec = [ ... 0.10E+00, ... 0.10E+00, ... 0.10E+00, ... 0.50E+00, ... 0.50E+00, ... 0.50E+00, ... 0.10E+01, ... 0.10E+01, ... 0.10E+01, ... 0.11E+01, ... 0.11E+01, ... 0.11E+01, ... 0.20E+01, ... 0.20E+01, ... 0.20E+01, ... 0.60E+01, ... 0.60E+01, ... 0.11E+02, ... 0.26E+02, ... 0.41E+02 ]; fx_vec = [ ... 0.7382350532339351E+00, ... 0.9083579897300343E+00, ... 0.9886559833621947E+00, ... 0.3014646416966613E+00, ... 0.7793286380801532E+00, ... 0.9918490284064973E+00, ... 0.9516258196404043E-01, ... 0.6321205588285577E+00, ... 0.9932620530009145E+00, ... 0.7205974576054322E-01, ... 0.5891809618706485E+00, ... 0.9915368159845525E+00, ... 0.1018582711118352E-01, ... 0.4421745996289254E+00, ... 0.9927049442755639E+00, ... 0.4202103819530612E-01, ... 0.9796589705830716E+00, ... 0.9226039842296429E+00, ... 0.4470785799755852E+00, ... 0.7444549220718699E+00 ]; x_vec = [ ... 0.30E-01, ... 0.30E+00, ... 0.15E+01, ... 0.75E-01, ... 0.75E+00, ... 0.35E+01, ... 0.10E+00, ... 0.10E+01, ... 0.50E+01, ... 0.10E+00, ... 0.10E+01, ... 0.50E+01, ... 0.15E+00, ... 0.15E+01, ... 0.70E+01, ... 0.25E+01, ... 0.12E+02, ... 0.16E+02, ... 0.25E+02, ... 0.45E+02 ]; if ( n_data < 0 ) n_data = 0; end n_data = n_data + 1; if ( n_max < n_data ) n_data = 0; a = 0.0; x = 0.0; fx = 0.0; else a = a_vec(n_data); x = x_vec(n_data); fx = fx_vec(n_data); end return end