Data Visualization | Towards Data Science https://towardsdatascience.com/tag/data-visualization/ Publish AI, ML & data-science insights to a global community of data professionals. Mon, 15 Dec 2025 15:55:13 +0000 en-US hourly 1 https://wordpress.org/?v=6.8.3 https://towardsdatascience.com/wp-content/uploads/2025/02/cropped-Favicon-32x32.png Data Visualization | Towards Data Science https://towardsdatascience.com/tag/data-visualization/ 32 32 Geospatial exploratory data analysis with GeoPandas and DuckDB https://towardsdatascience.com/geospatial-exploratory-data-analysis-with-geopandas-and-duckdb/ Mon, 15 Dec 2025 13:17:00 +0000 https://towardsdatascience.com/?p=607897 In this article, I’ll show you how to use two popular Python libraries to carry out some geospatial analysis of traffic accident data within the UK. I was a relatively early adopter of DuckDB, the fast OLAP database, after it became available, but only recently realised that, through an extension, it offered a large number […]

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]]> The Machine Learning “Advent Calendar” Day 5: Gaussian Mixture Model in Excel https://towardsdatascience.com/the-machine-learning-advent-calendar-day-5-gmm-in-excel/ Fri, 05 Dec 2025 17:00:00 +0000 https://towardsdatascience.com/?p=607838 This article introduces the Gaussian Mixture Model as a natural extension of k-Means, by improving how distance is measured through variances and the Mahalanobis distance. Instead of assigning points to clusters with hard boundaries, GMM uses probabilities learned through the Expectation–Maximization algorithm – the general form of Lloyd’s method.

Using simple Excel formulas, we implement EM step by step in 1D and 2D, and we visualise how the Gaussian curves or ellipses move during training. The means shift, the variances adjust, and the shapes gradually settle around the true structure of the data.

GMM provides a richer, more flexible way to model clusters, and becomes intuitive once the process is made visible in a spreadsheet.

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]]> The Machine Learning “Advent Calendar” Day 3: GNB, LDA and QDA in Excel https://towardsdatascience.com/the-machine-learning-advent-calendar-day-3-gnb-lda-and-qda-in-excel/ Wed, 03 Dec 2025 16:30:00 +0000 https://towardsdatascience.com/?p=607802 From local distance to global probability

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]]> Metric Deception: When Your Best KPIs Hide Your Worst Failures https://towardsdatascience.com/metric-deception-when-your-best-kpis-hide-your-worst-failures/ Sat, 29 Nov 2025 15:00:00 +0000 https://towardsdatascience.com/?p=607765 The most dangerous KPIs aren’t broken; they’re the ones trusted long after they’ve lost their meaning.

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]]> I Cleaned a Messy CSV File Using Pandas .  Here’s the Exact Process I Follow Every Time. https://towardsdatascience.com/i-cleaned-a-messy-csv-file-using-pandas-heres-the-exact-process-i-follow-every-time/ Wed, 26 Nov 2025 19:13:17 +0000 https://towardsdatascience.com/?p=607742 Stop guessing at data cleaning. Use this repeatable 5-step Python workflow to diagnose and fix the most common data flaws.

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]]> Natural Language Visualization and the Future of Data Analysis and Presentation https://towardsdatascience.com/natural-language-visualization-and-the-future-of-data-analysis-and-presentation/ Fri, 21 Nov 2025 14:00:00 +0000 https://towardsdatascience.com/?p=607697 Will conversational interaction replace SQL queries, KPI reports, and dashboards?

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]]> Data Visualization Explained (Part 5): Visualizing Time-Series Data in Python (Matplotlib, Plotly, and Altair) https://towardsdatascience.com/data-visualization-explained-part-5-visualizing-time-series-data-in-python-matplotlib-plotly-and-altair/ Thu, 20 Nov 2025 15:30:00 +0000 https://towardsdatascience.com/?p=607688 An explanation of time-series visualization, including in-depth code examples in Matplotlib, Plotly, and Altair.

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]]> TDS Newsletter: How Compelling Data Stories Lead to Better Business Decisions https://towardsdatascience.com/tds-newsletter-how-compelling-data-stories-lead-to-better-business-decisions/ Thu, 13 Nov 2025 14:39:00 +0000 https://towardsdatascience.com/?p=607653 Why data-driven stories remain an evergreen tool for practitioners

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]]> The Ultimate Guide to Power BI Aggregations https://towardsdatascience.com/power-bi-aggregations-the-ultimate-guide/ Wed, 12 Nov 2025 20:28:02 +0000 https://towardsdatascience.com/?p=607612 Aggregations are one of the most powerful features in Power BI — learn how to leverage this feature to improve the performance of your Power BI solution

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]]> Why Storytelling With Data Matters for Business and Data Analysts https://towardsdatascience.com/why-storytelling-with-data-matters-for-business-and-data-analysts/ Mon, 10 Nov 2025 19:16:43 +0000 https://towardsdatascience.com/?p=607596 Data is driving the future of business and here’s how you can be prepared for that future

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]]> Does More Data Always Yield Better Performance? https://towardsdatascience.com/does-more-data-always-yield-better-performance/ Mon, 10 Nov 2025 18:47:18 +0000 https://towardsdatascience.com/?p=607593 Exploring and challenging the conventional wisdom of “more data → better performance” by experimenting with the interactions between sample size, attribute set, and model complexity.

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]]> Beyond Numbers: How to Humanize Your Data & Analysis https://towardsdatascience.com/beyond-numbers-how-to-humanize-your-data-analysis/ Fri, 07 Nov 2025 14:00:00 +0000 https://towardsdatascience.com/?p=607579 The scintillating grid optical illusion is a perfect metaphor for how raw data can mislead us, causing us to see false trends. To escape the "data-rich, action-poor" paradox, organizations should need data humanization.

This approach focuses on turning abstract metrics (the what) into clear, actionable stories (the why). It requires new roles like "Data Artisans," a core competency in "Data Storytelling," and a focus on proving the financial Impact (ROI) of these clearer insights.

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]]> What Building My First Dashboard Taught Me About Data Storytelling https://towardsdatascience.com/what-building-my-first-dashboard-taught-me-about-data-storytelling/ Tue, 04 Nov 2025 20:12:00 +0000 https://towardsdatascience.com/?p=607558 Why clarity beats complexity when turning data into stories people actually understand

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]]> Using NumPy to Analyze My Daily Habits (Sleep, Screen Time & Mood) https://towardsdatascience.com/using-numpy-to-analyze-my-daily-habits-sleep-screen-time-mood/ Tue, 28 Oct 2025 18:19:04 +0000 https://towardsdatascience.com/?p=607513 Can I use NumPy to figure out how my habits affect my mood and productivity?

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]]> The Power of Framework Dimensions: What Data Scientists Should Know https://towardsdatascience.com/the-power-of-framework-dimensions-what-data-scientists-should-know/ Sun, 26 Oct 2025 16:00:00 +0000 https://towardsdatascience.com/?p=607491 Practical guidance and a case study

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]]> Data Visualization Explained (Part 4): A Review of Python Essentials https://towardsdatascience.com/data-visualization-explained-part-4-a-review-of-python-essentials/ Sat, 25 Oct 2025 16:00:00 +0000 https://towardsdatascience.com/?p=607484 Learn the foundations of Python to take your data visualization game to the next level.

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]]> Hidden Gems in NumPy: 7 Functions Every Data Scientist Should Know https://towardsdatascience.com/hidden-gems-in-numpy-7-functions-every-data-scientist-should-know/ Tue, 21 Oct 2025 17:33:00 +0000 https://towardsdatascience.com/?p=607447 I’ve been learning data analytics for a year now. So far, I can consider myself confident in SQL and Power BI. The transition to Python has been quite exciting. I’ve been exposed to some neat and smarter approaches to data analysis. After brushing up on my skills on the Python fundamentals, the ideal next step […]

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]]> Building A Successful Relationship With Stakeholders https://towardsdatascience.com/building-a-successful-relationship-with-stakeholders-2/ Tue, 14 Oct 2025 18:05:48 +0000 https://towardsdatascience.com/?p=607387 Show your value by moving beyond the technical

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]]> Data Visualization Explained (Part 3): The Role of Color https://towardsdatascience.com/data-visualization-explained-part-3-the-role-of-color/ Wed, 08 Oct 2025 12:30:00 +0000 https://towardsdatascience.com/?p=607356 A simple and powerful guide to using color for more impactful data stories.

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]]> Build a Data Dashboard Using HTML, CSS, and JavaScript https://towardsdatascience.com/build-a-data-dashboard-using-html-css-javascript/ Fri, 03 Oct 2025 14:00:00 +0000 https://towardsdatascience.com/?p=607333 A framework-free guide for Python programmers

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