function [ n_data, x, fx ] = abram2_values ( n_data ) %*****************************************************************************80 % %% ABRAM2_VALUES returns some values of the Abramowitz2 function. % % Discussion: % % The function is defined by: % % ABRAM2(x) = Integral ( 0 <= t < infinity ) t^2 * exp( -t^2 - x / t ) dt % % The data was reported by McLeod. % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 15 September 2004 % % Author: % % John Burkardt % % Reference: % % Milton Abramowitz and Irene Stegun, % Handbook of Mathematical Functions, % US Department of Commerce, 1964. % % Allan McLeod, % Algorithm 757, MISCFUN: A software package to compute uncommon % special functions, % ACM Transactions on Mathematical Software, % Volume 22, Number 3, September 1996, pages 288-301. % % 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 X, the argument of the function. % % Output, real FX, the value of the function. % n_max = 20; fx_vec = [ ... 0.44213858162107913430E+00, ... 0.43923379545684026308E+00, ... 0.42789857297092602234E+00, ... 0.38652825661854504406E+00, ... 0.26538204413231368110E+00, ... 0.16848734838334595000E+00, ... 0.13609200032513227112E+00, ... 0.11070330027727917352E+00, ... 0.82126019995530382267E-01, ... 0.74538781999594581763E-01, ... 0.67732034377612811390E-01, ... 0.35641808698811851022E-01, ... 0.17956589956618269083E-01, ... 0.94058737143575370625E-02, ... 0.50809356204299213556E-02, ... 0.28149565414209719359E-02, ... 0.53808696422559303431E-03, ... 0.44821756380146327259E-04, ... 0.46890678427324100410E-05, ... 0.20161544850996420504E-08 ]; x_vec = [ ... 0.0019531250E+00, ... 0.0078125000E+00, ... 0.0312500000E+00, ... 0.1250000000E+00, ... 0.5000000000E+00, ... 1.0000000000E+00, ... 1.2500000000E+00, ... 1.5000000000E+00, ... 1.8750000000E+00, ... 2.0000000000E+00, ... 2.1250000000E+00, ... 3.0000000000E+00, ... 4.0000000000E+00, ... 5.0000000000E+00, ... 6.0000000000E+00, ... 7.0000000000E+00, ... 10.0000000000E+00, ... 15.0000000000E+00, ... 20.0000000000E+00, ... 40.0000000000E+00 ]; if ( n_data < 0 ) n_data = 0; end n_data = n_data + 1; if ( n_max < n_data ) n_data = 0; x = 0.0; fx = 0.0; else x = x_vec(n_data); fx = fx_vec(n_data); end return end