Accelerated R with CUDA on Linux

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.

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Scientific consensus: Earth’s climate is warming

NOTE: This is a mirror of the page climate.nasa.gov/scientific-consensus on 2016-12-16, posted here for safe keeping.

Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record. Data sources: NASA's Goddard Institute for Space Studies, NOAA National Climatic Data Center, Met Office Hadley Centre/Climatic Research Unit and the Japanese Meteorological Agency.
Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record. Data sources: NASA’s Goddard Institute for Space Studies, NOAA National Climatic Data Center, Met Office Hadley Centre/Climatic Research Unit and the Japanese Meteorological Agency.

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.
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TCCON

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).

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Visualising OCO-2 XCO2 in R with DeltaRho

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.

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Installing every CRAN package in R on CentOS 7

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.

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R on Hadoop with Tessera RHipe

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.

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Converting HDF5 to CSV

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.

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