Multiple plots in matplotlib

Question

I have the following code that draws two superimposed plots from a two-dimensional list using matplotlib:

for day in days:

    # Draw a green triangle
    plt.plot(day[0], len(day[1] * 100), 'g^')

    # Draw red dots
    for hour in day[1]:
        plt.plot(day[0], hour, 'ro')

This results in a plot like the following:

But I'd like the triangles to be connected with solid lines so that the evolution along the X-axis is seen more clearly. No matter what I replace 'g^' with I can't seem to draw solid lines here. How is this supposed to be done?

Thank you.

Answer 1

Welcome to Stack Overflow!

If you really want to loop through the data and plot it one-by-one you could do the following:

green_triangles,_ = plt.plot([],[],'g^')#Could be that you need 'g^-'. Can't test it now
for day in days:

    # Draw a green triangle
    X = np.append(green_triangles.get_xdata(), day[0])
    Y = np.append(green_triangles.get_ydata(), len(day[1] * 100))             
    green_triangles.set_xdata(X)
    green_triangles.set_ydata(Y)

    # Draw red dots
    for hour in day[1]:
        plt.plot(day[0], hour, 'ro')

Answer 2

You can just do two lines to make the triangles connected, it is not beautiful, but works:

# Draw a green triangles, as you said:
plt.plot(day[0], len(day[1] * 100), 'g^')
# another line to draw the green line:
plt.plot(day[0], len(day[1] * 100), 'g')

Or, after reading matplotlib documentation , you can write:

plt.plot(day[0], len(day[1] * 100), linestyle='solid', marker='^', color='g')

Answer 3

Just replace

plt.plot(day[0], len(day[1] * 100), 'g^')

with

plt.plot(day[0], len(day[1] * 100), '-g^')

Notice the additional - in the second line.