Plotting a function using matplotlib

Question

I have the following function

def procrustes(data1, data2, data3):
              ...

which returns

return mtx1, mtx2, mtx3_prime, disparity 

mxt1, mtx2 and mtx3_prime, are all arrays. disparity is a float

I want to plot mtx1, mtx2, mtx3_prime on a graph. how best can i do this? I tried

plt.plot(procrustes(data1, data2, data3))
plt.show()

but that returned a value error

ValueError: setting an array element with a sequence.