@tomleslie  thanks for the answer.

it is now saving in the following format:

[t = 0., x(t) = 1., y(t) = -3.5]
[t = .2500000000, x(t) = 1.3125, y(t) = -3.09375]
[t = .5000000000, x(t) = 1.75, y(t) = -2.375]
which is  3 vecrors. What if i want to save in a matrix and also just 't' and y''( i mean not all the paramters) and also just values ( not the names).

Thx