993 search results for "how to import image file to R"

Speed-reading files, revisited

December 29, 2009
By
Speed-reading files, revisited

In a post earlier this month, it seemed as though compressing a data file before reading it into R could save you some time. With some feedback from readers and further experimentation, we might need to revisit that conclusion To recap, in our previous experiment it took 170 seconds to read a 182Mb text file into R. But if...

Read more »

Image Compression with the SVD in R

December 17, 2009
By
Image Compression with the SVD in R

Over the next few posts, I’m going to be reviewing the use of R to implement the most commonly used matrix techniques for image manipulation. The code will be surprisingly simple to understand, because the real magic behind these techniques lies in the mathematics that R provides an abstract interface to. To start, I’m going

Read more »

Export Data Frames To Multi-worksheet Excel File

October 6, 2009
By
Export Data Frames To Multi-worksheet Excel File

A few weeks ago I needed to export a number of data frames to separate worksheets in an Excel file. Although one could output csv-files from R and then import them manually or with the help of VBA into Excel, I was after a more streamlined solution, as I would need to repeat this process

Read more »

How to Import MS Excel Data into R

September 26, 2009
By
How to Import MS Excel Data into R

s Sir Francis Bacon said, “Histories make men wise; poets witty; the mathematics subtile; natural philosophy deep; moral grave; logic and rhetoric able to contend.” And Windows stupid. He should have added the last sentence if he were a Windows user in this age. 1. Avoid Using M$ Excel A lot of R users often ask this question:

Read more »

RStudio v0.99 Preview: Graphviz and DiagrammeR

May 1, 2015
By
RStudio v0.99 Preview: Graphviz and DiagrammeR

Soon after the announcement of htmlwidgets, Rich Iannone released the DiagrammeR package, which makes it easy to generate graph and flowchart diagrams using text in a Markdown-like syntax. The package is very flexible and powerful, and includes: Rendering of Graphviz graph visualizations (via viz.js) Creating diagrams and flowcharts using mermaid.js Facilities for mapping R objects into graphs, diagrams, and flowcharts.

Read more »

Dockerizing a Shiny App

April 30, 2015
By

After a long pause of more than four months, I am finally back to post here. Unfortunately, many commitments prevented me keep posting, but coming back, i changed the deployment (now this blog runs entirely within a docker container with some other cool things I intend to post more forward) and wrote this post. 1. The post

Read more »

Turning Data Into Awesome With sqldf and pandasql

April 29, 2015
By
Turning Data Into Awesome With sqldf and pandasql

Both R and Python possess libraries for using SQL statements to interact with data frames. While both languages have native facilities for manipulating data, the sqldf and pandasql provide a simple and elegant interface for conducting tasks using an intuitive framework that’s widely used by analysts.         R and sqldf sqldf("SELECT COUNT(*) FROM df2 WHERE

Read more »

Downloading and Visualizing Seismic Events from USGS

April 28, 2015
By
Downloading and Visualizing Seismic Events from USGS

The unlucky events that took place in Nepal have flooded the web with visualization of the earthquakes from USGS. They normally visualize earthquakes with a colour scale that depends on the age of the event and a marker size that depends on magnitude. I remembered that some time ago I tested ways for downloading and visualizing data from USG...

Read more »

A simple explanation of rejection sampling in R

April 22, 2015
By
A simple explanation of rejection sampling in R

The central quantity in Bayesian inference, the posterior, can usually not be calculated analytically, but needs to be estimated by numerical integration, which is typically done with a Monte-Carlo algorithm. The three main algorithm classes for doing so are Rejection sampling Markov-Chain Monte Carlo (MCMC) sampling Sequential Monte Carlo (SMC) sampling I have previously given…

Read more »

My New Favorite Statistics & Data Analysis Book Using R

April 20, 2015
By
My New Favorite Statistics & Data Analysis Book Using R

(Note: The Amazon site may not be fully functional until mid-week as they complete their setup.) As of today, I now have a NEW FAVORITE introductory statistics textbook… the one I’ve always dreamed

Read more »