histogram with time bins from datetime vector

Question

I have a vector with dates (datetime) in python. How can I plot a histogram with 15 min bins from the occurrences on this vector?

Here is what I did:

StartTime = []
for b in myEvents:
    StartTime.append(b['logDate'].time())

As you see, I converted the dates into times. (I'm getting myEvents from a mongoDB query)

fig2 = plt.figure()
ax = fig2.add_subplot(111)
ax.grid(True,which='both')
ax.hist(StartTime,100)

The error I get is:

TypeError: can't compare datetime.time to float

I understand the error, but I can't figure out how to fix it.

Thank you very much for your help

Answer 1

If you want to bin by hour, minute, or second, it should be very easy:

ts = np.array([ datetime.time(random.randint(24),*random.randint(60,size=2)) for i in range(100) ])
hist([t.hour for t in ts], bins = 24) # to bin by hour

Furthermore, for fifteen minute bins, but the problem here is now the units are decimal hours:

hist([t.hour + t.minute/60. for t in ts], bins = 24*60/15)