我有这个数据集:
structure(list(time = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15), ttt1_1 = c(0, 15, 20, 30, 40, 50, 60, 70, 80, 90,
130, 160, 240, 320, 450), ttt1_2 = c(0, 17, 22, 34, 50, 50, 65,
75, 90, 120, 160, 200, 300, 400, 500), ttt1_3 = c(0, 19, 25,
36, 47, 60, 70, 86, 110, 130, 195, 2