>>141 今日は2次のルンゲ=クッタにしてみたｗ PROGRAM oppai2 PARAMETER (h = 0.2, a = 1.0, b = -1.0, c = -1.0, d = 1.0) t = 0.0 x = 3.0 y = 1.0 hh = h / 2.0 DO 10 i = 1, 200 t = i * h dx0 = (a + b * y) * x * hh dy0 = (c + d * x) * y * hh dx = (a + b * (y + dy0) ) * (x + dx0) * hh dy = (c + d * (x + dx0) ) * (y + dy0) * hh x = MAX(0.0, x + dx) y = MAX(0.0, y + dy) WRITE(6, *) x, y, t, i 10 CONTINUE END
