АРКТАНГЕНС function [ n_data, x, fx ] = arctan_values ( n_data ) %*****************************************************************************80 % %% ARCTAN_VALUES returns some values of the arc tangent function. % % Discussion: % % In Mathematica, the function can be evaluated by: % % ArcTan[x] % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 12 June 2007 % % Author: % % John Burkardt % % Reference: % % Milton Abramowitz, Irene Stegun, % Handbook of Mathematical Functions, % National Bureau of Standards, 1964, % ISBN: 0-486-61272-4, % LC: QA47.A34. % % Stephen Wolfram, % The Mathematica Book, % Fourth Edition, % Cambridge University Press, 1999, % ISBN: 0-521-64314-7, % LC: QA76.95.W65. % % 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 = 11; fx_vec = [ ... 0.00000000000000000000, ... 0.24497866312686415417, ... 0.32175055439664219340, ... 0.46364760900080611621, ... 0.78539816339744830962, ... 1.1071487177940905030, ... 1.2490457723982544258, ... 1.3258176636680324651, ... 1.3734007669450158609, ... 1.4711276743037345919, ... 1.5208379310729538578 ]; x_vec = [ ... 0.00000000000000000000, ... 0.25000000000000000000, ... 0.33333333333333333333, ... 0.50000000000000000000, ... 1.0000000000000000000, ... 2.0000000000000000000, ... 3.0000000000000000000, ... 4.0000000000000000000, ... 5.0000000000000000000, ... 10.000000000000000000, ... 20.000000000000000000 ]; 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