Today I gave a presentation for GSO(Graduate Student Organization) of our department, mainly about the idea of dynamic document and its implementation using knitr.
Here are the slides I showed in the talk, written with Markdown and knitr.
This is a pretty old topic in R graphics. A classical article in R NEWS, Non-standard fonts in PostScript and PDF graphics, describes how to use and embed system fonts in the PDF/PostScript device. More recently, Winston Chang developed the extrafont package, which makes the procedure much easier. A useful introduction article can be found in the readme page of extrafont, and also from the Revolution blog.
Now, we have another choice: the showtext package.
Dr. Hadley Wickham is the Chief Scientist of RStudio and Assistant Professor of Statistics at Rice University. He is the developer of the famous R package ggplot2 for data visualization and the author of many other widely used packages like plyr and reshape2. On Sep 13, 2013 he gave a talk at Department of Statistics, Purdue University, and later I (Yixuan) had a conversation with him (Hadley), talking about his own experience and interest on data visualization, data tidying, R programming and other related topics.
This title is a bit exaggerating since handwriting recognition is an advanced topic in machine learning involving complex techniques and algorithms. In this blog I’ll show you a simple demo illustrating how to recognize a single number (0 ~ 9) using R. The overall process is that, you draw a number in a graphics device in R using your mouse, and then the program will “guess” what you have input. It is just for FUN.
This binary package supports R 2.13.x (32-bit/64-bit) and MySQL 5.5.16 (32-bit/64-bit).
RMySQL 0.8-0 for MySQL 5.5.16
It’s well known that R is a memory based software, meaning that datasets must be copied into memory before being manipulated. For small or medium scale datasets, this doesn’t cause any troubles. However, when you need to deal with larger ones, for instance, financial time series or log data from the Internet, the consumption of memory is always a nuisance.
Just to give a simple illustration, you can put in the following code into R to allocate a matrix named x and a vector named y.