2676 search results for "GIS"

Histogram + Density Plot Combo in R

September 27, 2012
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Histogram + Density Plot Combo in R

Plotting a histogram using hist from the graphics package is pretty straightforward, but what if you want to view the density plot on top of the histogram? This combination of graphics can help us compare the distributions of groups.Let's use...

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The simplest Species Distribution Model in OpenBUGS & R

September 27, 2012
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This post demonstrates the simplest Species Distribution Model based on logistic regression for presence/absence data. I heavily simplified the example from Kéry (2010): Introduction to WinBUGS for Ecologists, Chapter 20.Read more →

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Continuous dispersal on a discrete lattice

September 27, 2012
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Continuous dispersal on a discrete lattice

Dispersal is a key process in many domains, and particularly in ecology. Individuals move in space, and this movement can be modelled as a random process following some kernel. The dispersal kernel is simply a probability distribution describing the distance travelled in a given time frame. Since space is continuous, it is natural to use

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Simplest possible heatmap with ggplot2

September 27, 2012
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Simplest possible heatmap with ggplot2

Featuring the lovely “spectral” palette from Colorbrewer. This really just serves as a reminder of how to do four things I frequently want to do: Make a heatmap of some kind of matrix, often a square correlation matrix Reorder a factor vari...

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structure and uncertainty, Bristol, Sept. 26

September 26, 2012
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structure and uncertainty, Bristol, Sept. 26

Another day full of interesting and challenging—in the sense they generated new questions for me—talks at the SuSTain workshop. After another (dry and fast) run around the Downs; Leo Held started the talks with one of my favourite topics, namely the theory of g-priors in generalized linear models. He did bring a new perspective on

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Modifying select off-diagonal items in a matrix

September 25, 2012
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This is something I have had the occasion to do, and never remember how, so this is legitimately a reminder to my future self of how to do things with off-diagonal elements of a matrix. Select rows and columns are easy: mat or mat, for...

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Two particular courses and other upcoming events

September 25, 2012
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Two particular courses and other upcoming events

Featured I’ll be leading two courses in the near future: Value-at-Risk versus Expected Shortfall 2012 October 30-31, London. 30th: “Addressing the critical challenges and issues raised by the Basel proposal to replace VaR with Expected Shortfall” 31st: “Variability in Value-at-Risk and Expected Shortfall” led by Patrick Burns Details at CFP Events. Finance with R Workshop … Continue reading...

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Visually-weighted regression plots, with Zelig

September 25, 2012
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Visually-weighted regression plots, with Zelig

As a follow-up to yesterday’s post on producing visually-weighted regression plots, here is some code which illustrates the production of similar plots, but using Zelig’s convenient modeling and simulation functions. This code was produced...

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Formula for Kickstarter Success: Copious Planning (just like real life)

September 24, 2012
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Formula for Kickstarter Success: Copious Planning (just like real life)

It seems like the press can’t wait two days between awful depressing articles about how Kickstarter encourages fraud, broken promises, and tears.  Today I’d like to take you through a project thatshipped — let’s see what we can learn.  I interviewed Diana Rodgers of Wonder Threads.     Diana sought funding to expand her tech … Continue reading...

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Use GBIF and googleVis to Make Maps with Species Occurrence Data

September 24, 2012
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Use GBIF and googleVis to Make Maps with Species Occurrence Data

This is a short follow up on THIS posting.. I will briefly show how to use the dismo- and the googeVis package to plot species occurrences on an interactive Google map, like the one below (HERE is the R-script)MapID2ce4348e653