The R programming language uses Basic Linear Algebra Subprograms (BLAS) for performing common linear algebra operations such as vector addition, scalar multiplication, dot products, linear combinations, and matrix multiplication. R includes Netlib BLAS by default. Significant performance gains can be achieved by replacing that with a different BLAS library such as OpenBLAS or ATLAS.
Further gains are possible by intercepting certain calls to BLAS with NVIDIA’s NVBLAS. Operations that can benefit from running on a GPU will be automatically redirected to cuBLAS without any modification to your R code.
Continue reading Accelerated R with CUDA on Linux
NASA JPL’s Orbiting Carbon Observatory 2 (OCO-2) was launched into sun-synchronous orbit around the Earth on July 2, 2014. It carries 3 grated spectrometers for measuring the spectrum of sunlight reflected off the surface of the earth, which is used to calculate the average concentration of Carbon Dioxide in the column of atmosphere beneath the satellite (XCO2). It takes 16 days to provide full coverage of the Earth’s surface.
I am using the R packages datadr and Trelliscope from the DeltaRho project (formerly called Tessera.io) to explore and visualise the XCO2 observations from the OCO-2 Level 2 Lite version 7R data product.
Continue reading Visualising OCO-2 XCO2 in R with DeltaRho
Why would you want to install every CRAN package? That’s a good question.
Step 1: Install CentOS 7 Linux.
Some R packages will not install without an active X window session, so if you are not logged in to a graphical interface on the machine you will need to connect via SSH with X-forwarding enabled, such as with PuTTY and VcXsrv on Windows.
Most of this guide must be run from the Linux terminal as the user who will be running R. That user must be allowed to run commands as root with sudo.
Continue reading Installing every CRAN package in R on CentOS 7
Does your internet feel slower in the evenings or on weekends? This Python script downloads a 3MB file every 5 minutes to log your download speed in a CSV file. You can change the frequency or choose a different file by editing the script.
Continue reading Plotting your internet speed
This tutorial will show you how to perform parallel computation on a Hadoop cluster in R using Rhipe, with CSV files as input and output.
The EVE Online computer game universe consists of 5201 solar systems for players to explore and conquer in virtual spaceships. Each solar system is connected to an average 2.6 other systems by jump gates which allow instantaneous travel between systems.
Continue reading R on Hadoop with Tessera RHipe
Hierarchical Data Format 5 is a popular file format for storing and managing large amounts of data. It is the format used by NASA for their ACOS and OCO-2 data products, which both contain (among other things) column-averaged CO2 in units of dry-air mole fraction (Xco2). This tutorial demonstrates how to extract the average daily Xco2 value – and total reading count per day – from the HDF5 files into a CSV file for analysis in Excel or Gnumeric.
Continue reading Converting HDF5 to CSV