Introducing Tidyverse-Part 1:Tidy Data

In an ideal world, a data analysis process is as simple as-read in data, select a suitable model to fit in data, obtain statistical estimates, and finally, interpret the analysis results. Sounds simple and straight forward, isn’t it? But, in reality, it’s often not that simple!Data is always messy and often times we need to clean our data before we can make any sense of it. Moreover, some researchers found that more than 80% of data analysis is actually spent on data preparation or data manipulation (Dasu & Johnson, 2003), so that the data is transformed into a usable format before you even think about analysis.

Load “rJava” package on R

Recently, some R users (include myself) find that they are unable to load ‘rJava’ package in R. This creates a big headache to the regular R user, since ‘rJava’ package is a core dependent package for most of txt processing R packages, like xlsx, tabulizer, Rwordseg, etc.). It is crucial to fix this issue and load ‘rJava’ package on R successfully. Therefore, I’ve spent some time to find a way to make it work.

Parallel Analysis: Determining the Dimensionality of Data

1 WHAT IS PARALLEL ANALYSIS 2 METHODOLOGY 3 PARALLEL ANALYSIS IN R Recently, my colleague asked me to review a state assessment tech report. In the tech report, a section-“Parallel Analysis” really caught my eyes. I have done parallel analysis multiple times in the past. However, I have never thought about this topic in a systematical way. It is always a good memory refreshing opportunity. Therefore, I take this tech report reviewing opportunity to dig down the parallel analysis.

Bad Habits in R programming from Nice-R-Code site

Recently, I’ve prepared/refreshed my old programming talk materials. It was a talk I gave internally to all the summer interns in 2018. I found an very interesting and good post from the web. This web post gives a lot of good and bad programming examples. I thought it might be worthwhile for me to share the post content here so that people including myself could be benefited from it in the future.

Fight with TinyTex and Rmarkdown can't knit to PDF on my PC

A little bit History I started to learn R markdown since 2018. Figure 1: R Markdown After attending RStudio conference 2019 @Austin, I decided write my tech report for project in R markdown. Figure 2: RStudio Conf 2019 Although it’s a tough process, I finally nailed it and wrote at least 2 tech report in Rmarkdown then produced the final tech report in PDF for client.

First blog and some words

Yihui Xie Keith McNulty David Robinson Useful links This is the first blog I created after I put my personal website online. This is the second time I’ve built my personal website. Last time, when I built my first one, I was still in graduate school fighting for my dissertation. It seems like a Déjà vu, but two websites serve as two different purposes. My first website was mainly used for advertising and job hunting.

A Comparison of Parameter Recovery Using different Computer Programs and R-Packages in Estimating the Graded Response Model