Thanks a lot, @tomleslie

When I try to run your code I can get the graph, but there are no (x,y) axes. I don't know if this is because I am using an older version of the program. I can get the dashed line and this is a good start.

Greetings

Thanks a lot , @Preben Alsholm.

However, when I try to run the program a few Errors appears and I cannot get the graph:

p0:=DEtools:-DEplot([ode1, ode2], [x(t), y(t)], t = 0 .. 1, x = -100 .. 100, y = -100 .. 100,
 [[x(0) = 0, y(0) = 0]],arrows = medium,color="Green"):
Error, `DEtools` does not evaluate to a module
plots:-display(P~(L1,opts),p0);
Error, (in plots:-display) expecting plot structure but received: p0
plots:-display(P~(L1,-0.9..10,opts),p0);
Error, (in plots:-display) expecting plot structure but received: p0

Maybe I am not using your code correctly.

Greetings

@Rouben Rostamian Greetings

@Rouben Rostamian  

Thanks a lot, Rouben.

However, it is very important to me the existence of the arrows in the plot and whenever I try to use the command "arrows", the problem with the Float... apprears again. I do not understand why there is no problem if the arrows are not in the plot.

Greetings