How to plot events on time on using matplotlib

Question

I have 3 lists, each containing numbers, representing a time. The time represents occuring of an event. For example, in this A, I have a number for each occurence of event A. I want to represent this data on a graph. In either of the following two ways:

1)

aabaaabbccacac

2)

a-> xx xxx    x x
b->   x   xx  
c->         xx x x

Answer 1

You could use plt.hlines:

import matplotlib.pyplot as plt
import random
import numpy as np
import string

def generate_data(N = 20):
    data = [random.randrange(3) for x in range(N)]
    A = [i for i, x in enumerate(data) if x == 0]
    B = [i for i, x in enumerate(data) if x == 1]
    C = [i for i, x in enumerate(data) if x == 2]
    return A,B,C

def to_xy(*events):
    x, y = [], []
    for i,event in enumerate(events):
        y.extend([i]*len(event))
        x.extend(event)
    x, y = np.array(x), np.array(y)
    return x,y

def event_string(x,y):
    labels = np.array(list(string.uppercase))        
    seq = labels[y[np.argsort(x)]]
    return seq.tostring()

def plot_events(x,y):
    labels = np.array(list(string.uppercase))    
    plt.hlines(y, x, x+1, lw = 2, color = 'red')
    plt.ylim(max(y)+0.5, min(y)-0.5)
    plt.yticks(range(y.max()+1), labels)
    plt.show()

A,B,C = generate_data(20)
x,y = to_xy(A,B,C)
print(event_string(x,y))
plot_events(x,y)

yields

BBACBCACCABACCBCABCC