# Tutorial :Matplotlib: plotting discrete values ### Question:

I am trying to plot the following !

``from numpy import *  from pylab import *  import random    for x in range(1,500):      y = random.randint(1,25000)      print(x,y)         plot(x,y)    show()  ``

However, I keep getting a blank graph (?). Just to make sure that the program logic is correct I added the code `print(x,y)`, just the confirm that (x,y) pairs are being generated.

(x,y) pairs are being generated, but there is no plot, I keep getting a blank graph.

Any help ?

### Solution:1

First of all, I have sometimes had better success by doing

``from matplotlib import pyplot  ``

instead of using pylab, although this shouldn't make a difference in this case.

I think your actual issue might be that points are being plotted but aren't visible. It may work better to plot all points at once by using a list:

``xPoints = []  yPoints = []  for x in range(1,500):      y = random.randint(1,25000)      xPoints.append(x)      yPoints.append(y)  pyplot.plot(xPoints, yPoints)  pyplot.show()  ``

To make this even neater, you can use generator expressions:

``xPoints = range(1,500)  yPoints = [random.randint(1,25000) for _ in range(1,500)]  pyplot.plot(xPoints, yPoints)  pyplot.show()  ``

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
Previous
Next Post »