Jake

Python

Memray memory profiler for Python: initial impression

As a developer, you understand that optimizing your Python code for speed is not always sufficient. The memory usage of your program can become a significant bottleneck, particularly when working with large datasets or complex data structures. Enter Memray, a recent addition to the arsenal of tools available to Python

Wireless

Water-filling algorithm implemented using Matlab & Octave

In this post, I'm going to show you how to implement the water-filling algorithm using Matlab & Octave. Matlab is a great numerical computations tool, which has been widely adopted by engineers and scientists for all sorts of numerical computations. Water-filling is a generic method for allocating transmission power over (equalizing)

Python

Exploring the Best Python Libraries for Data Visualization

Introduction to essential data visualization libraries for data scientists. Find the best package to visualize your data.

Matlab

Convex Optimization with Octave: Status Check 2022

Octave [https://www.gnu.org/software/octave/index] is a fantastic open-source alternative to Matlab. It provides more-or-less compatible core functionality to Matlab by Mathworks. This is great for those who like the hassle-free approach that Matlab provides for numerical computation, but do not want to or can't buy an

Wireless

The Water-Filling Algorithm: In-depth Explanation

What is the capacity optimal way of allocating power over multiple simultaneous transmissions? This is a common question that arises time and time again in communications. In general, it is not an easy question to answer. In many cases, the problem turns out to be NP-hard, and we need to

Wireless

Binary Symmetric Channel

The binary symmetric channel (BSC) is one of the simplest channel models to consider. It is usually the starting point when we begin to study information and coding theory. This model is really worth spending some time and effort to understand as it builds up the foundation for more complex

Python

How to Do Cross-Correlation in Python: 4 Different Methods

💡Update 22.6.2022: Fixed date set generation. Cross-correlation is a basic signal processing method, which is used to analyze the similarity between two signals with different lags. Not only can you get an idea of how well the two signals match with each other, but you also get the

Rust with Serverless Framework: Introduction

Introduction on how to deploy simple Lambda function in AWS using Rust programming language.

Python

Convex Optimization in Python: 3 Essential Packages

Python has taken a big role in scientific computation and engineering. Packages, such as NumPy and SciPy, are heavily relied on in various computational applications and day-to-day research. How about computational optimization? We will have a look at the 3 most popular Python packages for computational optimization. More specifically, we

Python

Python for Time Series Analysis: 4 Techniques for Autocorrelation Function Calculation

Autocorrelation is a function that provides a correlation of a data set with itself on different delays (lags). This has many applications in statistics and signal processing. This subject was touched on in our previous post on how to write a pitch detection algorithm in Python using autocorrelation. Also if

AWS Cognito Authentication with Grafana Part 2: User roles

In this second installment of the AWS Cognito IDP for the Grafana series, we will see how to assign user roles based on the Cognito groups that the user is assigned to. In short, we will create a user group 'Admin' in AWS Cognito and assign the Admin right in

How to prevent screen flickering and tearing on KDE?

Screen flickering and tearing can be super annoying while you are trying to capture a full-screen recording of your screen. This is usually caused by a compositing window manager [https://en.wikipedia.org/wiki/Compositing_window_manager], which quite often is the case these days. Compositors are visually great and

AWS Cognito Authentication with Grafana Part 1: Local setup

In the AWS Cognito authentication with Grafana series, I will walk through how to set up Grafana with AWS Cognito user authentication. There are a few resources for this lying around in the Grafana forums and StackOverflow, but all of them are partial. In this first part, I'll show you

Python

Pitch detection using Python and autocorrelation

Pitch detection algorithm in python. Using autocorrelation as the dominant frequency detection tool.

Wireless

What are the Degrees-of-Freedom of a MIMO point-to-point channel?

The intuition behind degrees-of-freedom in a wireless channel is to describe the number of interference-free transmissions that the channel can support simultaneously. This is also sometimes called the multiplexing gain.

Python

Working with pointer arrays in pybind11

Pybind11 provides convient interface for C++ API. This header-only library is lightweight, easy to build, and include in a CMake project. In this post, I'm going to tackle a specific problem of working with pointer arrays in your C++ API.

Migrating Grafana from SQLite to PostgreSQL database

Grafana supports SQLite3, PostgreSQL, and MySQL backend databases, SQLite being the default one. All of these have their own benefits, but migrating from one to another can be a daunting task. In this post, I'm going to show you how we managed to migrate from SQLite3 backend to PostgreSQL as

Visualization

Interactive Chart.js visualization

We are going to build an interactive multi-chart visualization using chart.js. We will illustrate the inner state of the water-filling algorithm, which we implemented in our previous post. The illustration uses only HTML5 and Javascript. We use a range slider to move around different steps of the algorithm. For

Wireless

Water-filling algorithm explained and implemented in Python

In this post, I'm going to show you how the water-filling algorithm works, and how to implement it in Python. For a more in-depth overview of the water-filling algorithm, check our post showing the algorithm's behavior and derivation.   The water-filling algorithm: in-depth explanationAn in-depth explanation of how the water-filling algorithm

What is the rate of convergence for the bisection search algorithm?

Consider the initial search region to be \(L\). On each step, we halve the search region size. That is, after the \(n^\text{th}\) step, the remaining search region is \[l_n = {L \over {2^n}}\]. Let's set the convergence criterion (\(\epsilon\)) w.r.t. the size of the remaining

Signal processing

Trivial ordinary least squares in C++ & Armadillo

Using plain C++ for complex numerical calculations can be a lot of work. Luckily, some libraries can do much of the heavy lifting. I'm going to show you how to use Armadillo [http://arma.sourceforge.net/] to solve simple ordinary least squares (OLS) fitting. I'm assuming that you have the

Visualization

Embed chart.js visualization in Ghost

There exist a variety of web visualization frameworks to choose from. Each of which has its own merits. I'm going to show a simple example of how to embed beautiful Charts into your Ghost posts using chart.js. All of the following code can be placed within a single HTML

Visualization

How to use LaTeX Math in Draw.io & Diagrams.net models

Making publication-quality system models with complex mathematical notation can be a tedious task. In the past, I've been using Inkscape with TexText. This combination works fine and can produce great-quality images. However, I found it is not ideal for models that are basically diagrams. As the interconnections between the items

Wireless

How to solve orthogonal channel sum-rate maximization with CVXPY?

The optimization tools and numerical computation tools for Python have come a long way. These days you can formulate and solve complex problems with only a couple of lines of code. In this post, I am going to show you how to formulate and solve the sum rate (throughput) maximization

Visualization

How to plot CSV with ParaView

ParaView is a fully-featured visualization software capable of great things. I am showing you how to quickly plot line series from CSV files. This tutorial is done with ParaView version 5.11. These are all pretty basic features, so they should be quite stable between updates. You can find the