One of the finest data visualization tool

(Note: Some phones may not be able to show the interactive plots. Please use a laptop if that’s the case.)

Why Do I Use Plotly?

I have written a series of articles on data visualization, including “Pandas-Bokeh to Make Stunning Interactive Plots Easy”, “Use Seaborn to Do Beautiful Plots Easy”, “Create Beautiful Geomap with Plotly” and now this one. My goal is to assist you to produce data visualization easily and proficiently. I have written articles on a variety of data science topics. For the ease of use, you can bookmark my summary post “Dataman Learning Paths — Build Your Skills, Drive Your Career” that lists the links to all articles.

So why…


I hope my previous articles “Explain Your Model with the SHAP Values”, “Explain Any Models with the SHAP Values — Use the KernelExplainer” and “The SHAP with More Elegant Charts” help you greatly in your work. This article open-sources my small waterfall chart Python class to help you produce waterfall charts. If you have not read the previous posts, I suggest you read it first and come back to this article.

A waterfall chart shows how an initial value is increased and decreased by a series of intermediate values, leading to a final value. …


The local beach is not far from where I live, so sometimes I go there to enjoy my solitude. I watch the ocean waves come and go, leaving a belt of wet sand. I watch my footprints along the wet sand appearing and disappearing. One day I had an aha moment. These footprints are like the data points in a time series, and the belt of the wet sand the acceptable range by a time series model. There are a few footprints outside the belt called the anomalies or outliers. When the belt covers the normal footprints, none of them…


I hope “Explain Your Model with the SHAP Values” and “Explain Any Models with the SHAP Values — Use the KernelExplainer” have helped you greatly in your work. In this article I will cover more novelty in the SHAP graphs. If you have not read the previous post, I suggest you read it first and come back to this article and the next article “Creating Waterfall Plots for the SHAP Values for All Models”.

A great realtor once inspired me with his professional house presentation. He first showed me the outlook of the house, the lawn, and the street location…


It has been almost 30 years since the American economist John B. Taylor proposed what has been known as the Taylor rule. The Taylor rule is quoted by news articles especially during the 2020 Corona Virus recession or other periods of economic turmoil. Fund managers and investors want to gauge its guidance on monetary policy. There are also debates by admirable economists concerning how closely the policymakers should follow its predictions., i.e., using it as a prescriptive tool or a benchmarking tool.

Maybe this is the first time you heard the Taylor rule, I will introduce the Taylor rule gently…


You may be an entrepreneur who focuses on operational efficiency. You may be a business analyst looking for insights in sophisticated operations. You may want to add the power of machine learning to increase productivity. Or you may need to propose a new process for change management. If any of the above apply to your endeavors, you may find this article highly relevant. This article advices and references the following areas:

  • Reinventing the business processes of the industry or other industries.
  • Adding data analytics to the pipeline
  • Adding the power of machine learning increase productivity
  • While sketching a business process…

Python is the dominate data science language, R is a mature data science language, and Julia is gaining its traction. Most companies want resumes to list a long list of programming languages. What is the best language for data scientists? I cannot tell you which language — Mandarin, English, Hindustani, Spanish, Arabic, Malay, Russian, Greek, or Hindi is superior, while many of you already speak fluently in multiple languages. For data scientists I will advise Python, R and Julia.

There are three goals in this article: (1) Because Julia is not as popular as Python and R as of today…


When we survey the behaviors of ants, we shall be amazed by their collective wisdom and their massive construction. African ants can build a nest that is 6 or 7 meters tall. Their nests not only can be 100 times to an individual ant, the patterns of the nests are sophisticated too. Do they all follow a grand blueprint for construction? Now let’s observe how they search for food. They start searching everywhere. Once they found food, they form a long trail that can be as long as a mile to carry food back to the nest. Do they listen…


I quickly fall in love with Streamlit after I tried it out to deploy my models. I like the smart code of Streamlit to make an interactive dashboard for the visual charts. I like its neat interface. My productivity seems boosted ten-fold (or at least I feel). So here I demonstrate a complex project to show how it is done in only a few lines of code. I will also compare and contrast it with Flask, which is a popular light-weight web framework for Python. …


In “Learning Object-Orient Programming with Python in 10 Minutes”, I use a cookie-cutter idea to explain the concept of object-oriented programming (OOP). Many readers like that analogy. If you have not read the previous article, I strongly encourage you to read it first. In this article I continue to use the cookie-cutter idea to explain an important technique “Inheritance” in OOP. Once you understand it, you will read other classes comfortably and write your classes more efficiently.

In this article I also introduce the Unified Modeling Language (UML) Diagram. An UML diagram visualizes the relationships between multiple classes and what…

Dr. Dataman

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