NDVI, risk assessment and developing countries

The Normalized Difference Vegetation Index (NDVI) estimates the greenness of plants covering the surface of the Earth by measuring the light reflected by the vegetation into space. The main idea behind the NDVI is that visible and near-infrared light is absorbed in different proportions by healthy and unhealthy plants: a green plant will reflect 50% of the near infrared-light it receives and only 8% of the visible light while an unhealthy plant will reflect respectively 40% and 30%. NDVI can then be used to quantitatively compare vegetation conditions across time and space (and indeed is quite widely used, a Google Scholar search on NDVI produced 60,500 hits).

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Thursday, 14 February 2013

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RSS r-bloggers.com

  • R Package for @racently
    I recently wrote about an API for @racently. The next logical step was to build a package which wraps the API so that the data can easily be pulled into R. The package is available here. It is still very much a work in progress: the API only exposes two endpoints, but both of them […]
  • celebRation 2020
    The year 2020 marks the 20th anniversary of the release of R version 1.0.0! To celebrate this, we are inviting the community of R users and developers for a two-day celebRation workshop/mini-conference on February 28-29th 2020 in Copenhagen. We kick off on 28th February with hands-on workshops on two hot topics, namely data visualization using […]
  • Practical Data Science with R 2nd Edition now in-stock at Amazon.com!
    Practical Data Science with R 2nd Edition is now in-stock at Amazon.com! Buy it for your favorite data scientist in time for the holidays!
  • lintools 0.1.3 is on CRAN
    Version 0.1.3 of the lintools package was accepted on CRAN today. This version brings a few internal improvements and switches the testing suite to the tinytest test infrastructure. lintools is provides basic manipulations of linear systems of equalities and inequalities … Continue reading →
  • Sponsorship: SatRdays and useR Groups
    SatRdays SatRdays are great. Low cost R events, held around the world. What's not to love! For the last year, we have been offering automatic sponsorship for all SatRday events. All the organisers have to do is complete a quick questionnaire and the money is sent on it's way. So far we have sponsored seven […]

RSS Simply Statistics

  • Is Artificial Intelligence Revolutionizing Environmental Health?
    NOTE: This post was written by Kevin Elliott, Michigan State University; Nicole Kleinstreuer, National Institutes of Health; Patrick McMullen, ScitoVation; Gary Miller, Columbia University; Bhramar Mukherjee, University of Michigan; Roger D. Peng, Johns Hopkins University; Melissa Perry, The George Washington University; Reza Rasoulpour, Corteva Agriscience, and Elizabeth Boyle, National Academies of Sciences, Engineering, and Medicine. […]
  • You can replicate almost any plot with R
    Although R is great for quickly turning data into plots, it is not widely used for making publication ready figures. But, with enough tinkering you can make almost any plot in R. For examples check out the flowingdata blog or the Fundamentals of Data Visualization book. Here I show five charts from the lay press […]
  • So You Want to Start a Podcast
    Podcasting has gotten quite a bit easier over the past 10 years, due in part to improvements to hardware and software. I wrote about both how I edit and record both of my podcasts about 2 years ago and, while not much has changed since then, I thought it might be helpful if I organized […]

RSS Statistical Modeling, Causal Inference, and Social Science