=====Function Descriptions=====
mean

The mean tool computes the arithmetic mean along the specified axis.

import numpy

my_array = numpy.array([ [1, 2], [3, 4] ])

print numpy.mean(my_array, axis = 0) #Output : [ 2. 3.]
print numpy.mean(my_array, axis = 1) #Output : [ 1.5 3.5]
print numpy.mean(my_array, axis = None) #Output : 2.5
print numpy.mean(my_array) #Output : 2.5

By default, the axis is None. Therefore, it computes the mean of the flattened array.

var

The var tool computes the arithmetic variance along the specified axis.

import numpy

my_array = numpy.array([ [1, 2], [3, 4] ])

print numpy.var(my_array, axis = 0) #Output : [ 1. 1.]
print numpy.var(my_array, axis = 1) #Output : [ 0.25 0.25]
print numpy.var(my_array, axis = None) #Output : 1.25
print numpy.var(my_array) #Output : 1.25

By default, the axis is None. Therefore, it computes the variance of the flattened array.

std

The std tool computes the arithmetic standard deviation along the specified axis.

import numpy

my_array = numpy.array([ [1, 2], [3, 4] ])

print numpy.std(my_array, axis = 0) #Output : [ 1. 1.]
print numpy.std(my_array, axis = 1) #Output : [ 0.5 0.5]
print numpy.std(my_array, axis = None) #Output : 1.118033988749895
print numpy.std(my_array) #Output : 1.118033988749895

By default, the axis is None. Therefore, it computes the standard deviation of the flattened array.

=====Problem Statement=====
You are given a 2-D array of size NXM.
Your task is to find:
The mean along axis 1
The var along axis 0
The std along axis None

=====Input Format=====
The first line contains the space separated values of N and M.
The next N lines contains M space separated integers.

=====Output Format=====
First, print the mean.
Second, print the var.
Third, print the std.

见题面

见题面