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.
Multiple studies published in peer-reviewed scientific journals1 show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources. Continue reading Scientific consensus: Earth’s climate is warming
The Total Carbon Column Observing Network (TCCON) is a global network of instruments that measure the amount of carbon dioxide, methane, carbon monoxide, nitrous oxide and other trace gases in the Earth’s atmosphere. There are two TCCON instruments in Australia: Darwin and Wollongong (and one nearby in Lauder, New Zealand).
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.
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.
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object. In this context it refers to the use of NASA’s orbiting satellite OCO-2 to observe characteristics of the Earth’s atmosphere, specifically the concentration of Carbon Dioxide (CO2).
NASA Jet Propulsion Laboratory has this week released the OCO-2 L2 Lite files. These files contain a subset of the information in the standard OCO-2 L2 product. They are meant to be significantly smaller but still contain all necessary information for typical science analyses.
The lite files also contain warn levels which indicate the quality of the data points. At warning level 0 we can be very certain about the quality. Above warning level 12 we can expect significant error, and data points above warning level 15 should not be used at all. To see how much data is excluded at different warning levels I have mapped the data points for the month of May 2015.
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.
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.