Average of multi-dimensional array in Python

Question

I have a temperature data that I keep as an array:

temp[month][day][hour][min]

Is there an easy way to get the hourly average of the data, which is the average of all values in the same hour? Similarly, the daily average?

Answer 1

You should be able to use these functions to get the needed averages:

def hourly_average(values, month, day, hour):
  hour_data = values[month][day][hour]
  # extract the values for every minute in the specified hour.
  minute_values = [hour_data[min] for min in xrange(0,60)]
  return sum(minute_values)/60

def daily_average(values, month, day):
  # extract the averages for every hour in the specified day.
  hour_values = [hourly_average(vales,month,day,hour) for hour in xrange(0,24)]
  # the average of the averages of the equally weighted parts is the average 
  # of the thing itself (?).
  return sum(hour_values)/24

Answer 2

You'll be interested in using numpy .

Something like this becomes as simple as:

import numpy

data_as_numpy_array = numpy.array(original_data)

hourly_averages = numpy.average(data_as_numpy_array, 3)

daily_averages = numpy.average(hourly_averages, 2)

In the second two lines, the second argument is the axis along which you wish to average. Here 3 is the axis of the minute data, and two the axis of the hour data.

You may also be interested in installing pylab and ipython. Pylab emulates the graphing/visualisation functionality of Matlab, and ipython is an enhanced interpreter with tab-completion and full command input (and output) history amongst other things.