Zhuo Yao, Ph.D.

Playing with the ‘playwith’ package 23mar10 Abilities of R for creating graphics is great, but one thing I always missed is the possibility of creating…

View More Playing with the ‘playwith’ package

I’ve covered a few topics in the past including the plyr package, which is kind of like “GROUP BY” for R, and the merge function…

View More Use SQL queries to manipulate data frames in R with sqldf package

By Josh Mills Introduction For those who are learning R and who may be well-versed in SQL, the sqldf package provides a mechanism to manipulate…

View More Manipulating Data Frames Using sqldf – A Brief Overview

In order to do something to a bunch of files at once, we first need a vector which contains the file paths of just the…

View More Programatically rename files (or do other stuff to them) in R

This question already has an answer here: read csv with dates and numbers with R statistical software 3 answers I am working on “Localization Data…

View More How to convert specific time format to timestamp in R?

Contents Time and Date Variables Time Operations The time data types are broken out into a separate section from the introductory section on data types.…

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Time Series Analysis This booklet itells you how to use the R statistical software to carry out some simple analyses that are common in analysing…

View More Using R for Time Series Analysis

SocialDataBlog’s kind reference in post Horizon plots with ggplot (not) motivated me to finish what the post started.  I knew that ggplot2 would be a little more…

View More Horizon on ggplot2

The Timely Portfolio blog via R-bloggers has recently published some interesting entries about the value of horizon plots for visual comparison of a number of time series. …

View More Horizon plots with ggplot (not)

In the third and last of the ggplot series, this post will go over interesting ways to visualize the distribution of your data. I will…

View More ggplot2: Cheatsheet for Visualizing Distributions