# Question:Problem in DEplot

## Question:Problem in DEplot

Maple

Hi everyone,

I have a problem with DEplot.

Here is the code:

restart;with(DEtools), with(plots), with(linalg):

z:=exp(I*((t/(2*Pi))+(2*Pi*j/3)));

f1:=Re((I/(2*Pi))((1/(subs(j=1,z)-(x(t)+I*y(t))))+(1/(subs(j=2,z)-(x(t)+I*y(t))))+(1/(subs(j=3,z)-(x(t)+I*y(t))))));

g1:=-1*Im((I/(2*Pi))((1/(subs(j=1,z)-(x(t)+I*y(t))))+(1/(subs(j=2,z)-(x(t)+I*y(t))))+(1/(subs(j=3,z)-(x(t)+I*y(t))))));

sys1:=[diff(x(t),t)=f1,diff(y(t),t)=g1]:

F := DEplot(sys1, [x(t), y(t)], t = -20 .. 10, x = -2 .. 2, y = -2 .. 2, [[x(0) =0, y(0) = 0]],linecolor = blue, thickness = 2, stepsize = .1, arrows = medium, color = red);

And I get this error:

Error, (in dsolve/numeric/process_input) input system must be an ODE system, got independent variables {t, 1/(exp(1/2*I*t/Pi+2/3*Pi)-x(t)-I*y(t))+2/(exp(1/2*I*t/Pi+4/3*Pi)-x(t)-I*y(t)), 1/(exp(1/2*I*t/Pi+2/3*Pi)-x(t)-I*y(t))+1/(exp(1/2*I*t/Pi+4/3*Pi)-x(t)-I*y(t))+1/(exp(1/2*I*t/Pi+2*Pi)-x(t)-I*y(t))}

In the beginning I have couple of intermediate functions but I removed them all to avoid adding implicitely independant variables.

Is someone able to see the problem?