Can't see line on Matplotlib, can see points

Question

I am trying to model an orbit using a 4th order Runge-Kutta method, which works and gives a good numerical output. My issue is that when I try and plot the orbit around a fixed point, I can only see it if I specify that each data point is a point. This code is below:

T, X, Y, V_X, V_Y = orbit(x, y, v_x, v_y)
results = [(X, Y)]
results = np.array(results) #converts the results list to an array that can be called upon for the values of x and y for the graph
X = results[:,0] #gets values for x for graph
Y = results[:,1] #gets values for y for graph
pp.axis('equal')
pp.plot(X, Y, 'o') #plots graph of above X and Y with circular points connected by a line.
pp.scatter(0,0, s=1000, color='g')
pp.show()

This gives an output of:

enter image description here

when I get rid of the 'o' in the pp.plot line, the line vanishes. My only thought is that the thickness is very narrow compared to the scales on the graph, but I have never had this issue before.

• gmds: Could you please provide some data to test your code on? Also, the fact that the line is multi-coloured suggests that multiple lines are being plotted. What are the shapes of X and Y?
• DavidG: I think it might be because results is not a simple array. Might be an array of tuples... Can you show what results looks like?

Answer 1

Test only this:

T, X, Y, V_X, V_Y = orbit(x, y, v_x, v_y)
pp.axis('equal')
pp.plot(X, Y) #plots graph of above X and Y with circular points connected by a line.
pp.scatter(0,0, s=1000, color='g')
pp.show()

• J. Smith: This has made the output one thick blue line, cutting down the time interval I was doing it over has also helped as the orbit does decay slowly. Thank you very much for your help with this!