function stroud_test205 ( ) %*****************************************************************************80 % %% TEST205 tests ELLIPSE_AREA_2D, ELLIPSE_CIRCUMFERENCE_2D, ELLIPSE_ECCENTRICITY_2D. % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 06 April 2009 % % Author: % % John Burkardt % seed = 123456789; fprintf ( 1, '\n' ); fprintf ( 1, 'TEST205\n' ); fprintf ( 1, ' ELLIPSE_AREA_2D returns the area of an ellipse.\n' ); fprintf ( 1, ' ELLIPSE_ECCENTRICITY_2D returns the\n' ); fprintf ( 1, ' eccentricity of an ellipse.\n' ); fprintf ( 1, ' ELLIPSE_CIRCUMFERENCE_2D returns the\n' ); fprintf ( 1, ' circumference of an ellipse.\n' ); fprintf ( 1, '\n' ); fprintf ( 1, ' R1 R2 E Circum Area\n' ); fprintf ( 1, '\n' ); for i = 1 : 5 if ( i == 1 ) r1 = 25.0; r2 = 20.0; else [ r1, seed ] = r8_uniform_01 ( seed ); [ r2, seed ] = r8_uniform_01 ( seed ); end e = ellipse_eccentricity_2d ( r1, r2 ); p = ellipse_circumference_2d ( r1, r2 ); area = ellipse_area_2d ( r1, r2 ); fprintf ( 1, ' %9f %9f %9f %10f %12f\n', r1, r2, e, p, area ); end fprintf ( 1, '\n' ); fprintf ( 1, ' (For the first example,\n' ); fprintf ( 1, ' the eccentricity should be 0.6,\n' ); fprintf ( 1, ' the circumference should be about 141.8).\n' ); return end