Nov 21Member-onlyUnderstanding Cohen’s KappaCohen’s Kappa, or quadratic weighted kappa, is a metric to measure agreement between two ratings. The Key idea of this metrics is comparing the probability of two classifiers actually agree and the probability two classifiers agree by accident. The formula for this metrics is: You may wonder why this…Data Science3 min readData Science3 min read
Aug 28Member-onlyGit and Github 101Github is one of the most essential tools for software engineers, data scientists, data analysts, or anyone need version control. If you are not familiar with Git, I would recommend the video from GitHub: what is GitHub? This article, I will introduce what is git and GitHub and share some…Github6 min readGithub6 min read
Jul 11Member-onlyTime Series Analysis and ARIMA modelTime series is a set of data points indexed in time order. Some typical example are annual s&p 500 index, daily temperature and website visit per second. All time series can be decomposed as a multiplicative or additive function of three components. S_t : seasonal factor 2. T_t: trend or…Time Series Analysis7 min readTime Series Analysis7 min read
Dec 25, 2022Member-onlyOn Unemployment — What happened since pandemic and what will be the job market outlook in 2023?There no short of job cutting news at the end of 2022. According to layoffs.fyi, 1003 companies cut 152,421 jobs. Walls street did not escape the trend. Goldman Sachs planed to lay off 4,000 employees, around 8% of its total headcount. …20234 min read20234 min read
Nov 25, 2022Member-onlyLet’s talk about weather — using rnoaa to access the NOAA weather dataHow is the weather? When I was asked about the question, I usually resort to google Weather + City. I feel winter this year is way warmer vs. LY, but how can I find this year and last year’s winter temperature? …Weather5 min readWeather5 min read
Oct 14, 2022Member-onlyThe Very Basics of a Statistical TestThere are multiple types of statistical tests, but they all share same basic elements, which are random variables, distribution, null/alternative hypothesis and critical value, and concepts that are generated from these elements, e.g., …Statistics5 min readStatistics5 min read
Oct 6, 2022Member-onlySpeed Up Your Tableau DashboardYou created a tableau dashboard and shared it with the leadership team, sales team, finance team and they came back to told you how they loved your dashboard that shared insights that was not captured before. …Tableau5 min readTableau5 min read
Sep 16, 2022Member-onlyNo more power point by hand — automate PPT creation by R OfficerAs a data scientist, you draw insights from data and present it in a informative and visually appealing way. There are good tools (Tableau, Looker, Power BI) to help you tell the story, while what if your boss prefers PowerPoint? It is not hard to make PowerPoint, but it takes…R6 min readR6 min read
Sep 9, 2022Member-onlyTableau Filters — Operation orders and examplesThere are 6 types of tableau filters. Understanding operational order of filters can of vital importance. This article is going to briefly explain the 6 types of filters and share 3 examples to differentiate the subtle details of different filters. Extract Filters and Data Source Filters applied on extract or…Tableau4 min readTableau4 min read
May 6, 2022Member-onlyAn overview of methods to create R Shiny Desktop AppsIn this article, I am going to discuss two ways of deploying the R Shiny App as a desktop app There are two ways of deploying the R Shiny Apps: Web Application Desktop Application Though the first method is convenient, and easy to share, it requires multiple approvals from IT/Finance…R Shiny7 min readR Shiny7 min read
