## How to Calculate the Weighted Average of a Numpy Array in Python?

Problem Formulation: How to calculate the weighted average of the elements in a NumPy array? Definition weighted average: Each array element has an associated weight. The weighted average is the sum of all array elements, properly weighted, divided by the sum of all weights. Here’s the problem exemplified: Quick solution: Before we discuss the solution … Read more

## How to Calculate the Average of a NumPy 2D Array?

NumPy is a popular Python library for data science focusing on arrays, vectors, and matrices. This article introduces the np.average() function from the NumPy library. When applied to a 1D array, this function returns the average of the array values. When applied to a 2D array, NumPy simply flattens the array. The result is the … Read more

## How to Index Elements in NumPy Arrays?

NumPy is a popular Python library for data science for array, vector, and matrix computations. This puzzle introduces basic indexing of elements in NumPy arrays. Problem Formulation: How to index elements in NumPy arrays? Indexing 1D Arrays with Positive Indices The most simple use of indexing is with the square bracket notation and positive integers: … Read more

## How to Calculate the Standard Deviation in NumPy?

Problem Formulation: How to calculate the standard deviation in NumPy? Differentiations: There are many different variants of this problem: Calculate the standard deviation of a 1D array Calculate the standard deviation of a 2D array Calculate the standard deviation of a 3D array Then you can also calculate the standard deviation along an axis: Calculate … Read more

## 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 … Read more

## How to Calculate Variance of Python NumPy Arrays?

Numpy is a popular Python library for data science focusing on arrays, vectors, and matrices. Did you already learn something new today? Let’s master the popular variance function in NumPy! Problem: How to calculate the variance of a NumPy array? Solution: To calculate the variance of a Python NumPy array x, use the function np.var(x). … Read more