# 2D array

## Python Numpy 101: How to Calculate the Row Variance of a Numpy 2D Array?

You can play with the following interactive Python code to calculate the variance of a 2D array (total, row, and column variance). Here’s another practical example: What is the output of this puzzle?*Advanced Level* (solution below) Numpy is a popular Python library for data science focusing on arrays, vectors, and matrices. This puzzle introduces a … ## How to Calculate the Weighted Average of a Numpy Array in Python?

NumPy’s average function computes the average of all numerical values in a NumPy array. When used without parameters, it simply calculates the numerical average of all values in the array, no matter the array’s dimensionality. For example, the expression np.average([[1,2],[2,3]]) results in the average value (1+2+2+3)/4 = 2.0. However, what if you want to calculate …

## Python Numpy 101: How to Calculate the Simple Average of a Numpy Array?

[python] import numpy as np # stock prices (3x per day) # [morning, midday, evening] solar_x = np.array( [[2, 3, 4], # day 1 [2, 2, 5]]) # day 2 print(np.average(solar_x)) [/python] What is the output of this puzzle? *Beginner Level* (solution below) Numpy is a popular Python library for data science focusing on arrays, …

## How to Calculate the Standard Deviation in Numpy?

Daily Data Science Puzzle [python] import numpy as np # daily stock prices # [open, close] google = np.array( [[1239, 1258], # day 1 [1262, 1248], # day 2 [1181, 1205]]) # day 3 # standard deviation y = np.std(google, axis=1) print(y == max(y)) [/python] What is the output of this puzzle? *Advanced Level* (solution …