Tue Oct 19 17:09:00 2021 rkf45_test(): Python version: 3.6.9 Test rkf45(). rkf45_test04 Solve a scalar equation using r8_rkf45: Y = 0.25 * Y * ( 1 - Y / 20 ) FLAG T Y Y Y_Exact Error 1 0.000000 1.000000 0.237500 1.000000 0.000000e+00 2 4.000000 2.503220 0.547479 2.503220 -1.979480e-08 2 8.000000 5.600091 1.008010 5.600091 -5.333619e-08 2 12.000000 10.277734 1.249036 10.277734 -1.365593e-08 2 16.000000 14.836827 0.957564 14.836827 -1.296748e-07 2 20.000000 17.730166 0.503057 17.730166 -1.486949e-08 rkf45_test05(): Solve a vector equation using r8_rkf45 Y(1) = Y(2) Y(2) = -Y(1) FLAG T Y(1) Y(2) 1 0.000000 1.000000 0.000000 2 0.523599 0.866025 -0.500000 2 1.047198 0.500000 -0.866025 2 1.570796 0.000000 -1.000000 2 2.094395 -0.500000 -0.866025 2 2.617994 -0.866025 -0.500000 2 3.141593 -1.000000 -0.000000 2 3.665191 -0.866025 0.500000 2 4.188790 -0.500000 0.866025 2 4.712389 -0.000000 1.000000 2 5.235988 0.500000 0.866025 2 5.759587 0.866025 0.500000 2 6.283185 1.000000 0.000000 rkf45_test06(): Solve a scalar equation using r8_rkf45 Y = 0.25 * Y * ( 1 - Y / 20 ) Use the special SINGLE_STEP mode which returns after every step. FLAG T Y dY/dt Y_Exact Error -1 0.000000 1.000000 0.237500 1.000000 0.000000e+00 -2 0.041660 1.009941 0.239735 1.009941 -8.881784e-16 -2 0.249959 1.061062 0.251192 1.061062 -1.210787e-11 -2 0.713324 1.183667 0.278403 1.183667 -1.496592e-09 -2 1.180501 1.320626 0.308356 1.320626 -3.293747e-09 -2 1.647719 1.472207 0.340959 1.472207 -5.347271e-09 -2 2.115781 1.639976 0.376375 1.639976 -7.680261e-09 -2 2.585631 1.825723 0.414765 1.825723 -1.031720e-08 -2 3.058299 2.031467 0.456281 2.031467 -1.328133e-08 -2 3.529150 2.256606 0.500498 2.256606 -1.643689e-08 2 4.000000 2.503220 0.547479 2.503220 -1.979480e-08 -2 4.488220 2.782961 0.598929 2.782961 -2.378853e-08 -2 4.984780 3.093895 0.653821 3.093895 -2.813670e-08 -2 5.491613 3.439951 0.712072 3.439951 -3.280206e-08 -2 6.011100 3.825756 0.773484 3.825756 -3.770927e-08 -2 6.546184 4.256793 0.837695 4.256793 -4.272149e-08 -2 7.100597 4.739668 0.904111 4.739668 -4.760528e-08 -2 7.550299 5.158183 0.956960 5.158183 -5.060731e-08 2 8.000000 5.600091 1.008010 5.600091 -5.333619e-08 -2 8.636956 6.264005 1.075529 6.264005 -5.543713e-08 -2 9.315213 7.015494 1.138659 7.015494 -5.453142e-08 -2 10.064284 7.890322 1.194366 7.890322 -4.807415e-08 -2 10.932839 8.947763 1.236160 8.947763 -3.122716e-08 2 12.000000 10.277734 1.249036 10.277734 -1.365593e-08 -2 13.064868 11.595150 1.218194 11.595150 -5.792645e-08 -2 14.062311 12.780518 1.153359 12.780518 -1.096609e-07 -2 15.031156 13.856458 1.064097 13.856458 -1.405578e-07 -2 15.851518 14.693374 0.974653 14.693374 -1.319892e-07 2 16.000000 14.836827 0.957564 14.836827 -1.296748e-07 -2 16.742410 15.515329 0.869764 15.515329 -1.101591e-07 -2 17.488264 16.130626 0.780193 16.130626 -8.258942e-08 -2 18.199253 16.655363 0.696327 16.655363 -5.600938e-08 -2 18.888597 17.108278 0.618405 17.108278 -3.151943e-08 -2 19.444298 17.435256 0.558962 17.435256 -2.300144e-08 2 20.000000 17.730166 0.503057 17.730166 -1.486949e-08 rkf45_test Normal end of execution. Tue Oct 19 17:09:00 2021