The unlucky events that took place in Nepal have flooded the web with visualization of the earthquakes from USGS. They normally visualize earthquakes with a colour scale that depends on the age of the event and a marker size that depends on magnitude. I remembered that some time ago I ... [Read more...]

In my previous post I said that my students are using data from NOAA for their research.NOAA in fact provides daily averages of several environmental parameters for thousands of weather stations scattered across the globe, completely free. In details, NOAA provides the following data: Mean temperature for the day ... [Read more...]

These days I am following a couple of master projects dealing with renewable energy potentials at the global scale. We wanted to try and compute these potential using only free data and see how far we could go.For wind speed there are plenty of resourc... [Read more...]

Some time ago I published an article on "The Cartographic Journal" regarding a method to automatically change the light azimuth in shaded relief representations.This method was based on clustering the aspect derivative of the DTM. The method was develo... [Read more...]

Today I wanted to do some point pattern analysis in R using the fantastic package spatstat.The problem was that I only had a point shapefile, so I googled a way to transform a shapefile into a ppp object (which is the point pattern object used by spats... [Read more...]

KML files are used to visualize geographical data in Google Earth. These files are written in XML and allow to visualize places and to attach additional data in HTML format.In these days I am working with the MIDAS database of wind measuring stations a... [Read more...]

A couple of years ago I found online a script to merge several .asc grids into a single file in R.I do not remember where I found it but if you have the same problem, the script is the following: setwd("c:/temp") library(rgdal) library(raster) # ... [Read more...]

Sometimes I have the need to reduce the number of images for a presentation or an article. A good way of doing it is putting multiple plot on the same tif or jpg file.R has multiple functions to achieve this objective and a nice tutorial for this topic... [Read more...]

For Christmas I decided to treat myself with an Arduino starter kit. I started doing some basic experiments and I quickly found out numerous website that sell every sort of sensor: from temperature and humidity, to air quality. Long story short, I bou... [Read more...]

Introduction I couple of weeks ago I had an idea for a website where people can collaborate to create the first real Audio Atlas, using the power of the Google Maps API. The problem was that I do some programming in R but I did know very few things about ... [Read more...]

Yesterday I wanted to create a box-plot for a small dataset to see the evolution of 3 stations through a 3 days period. I like box-plots very much because I think they are one of the clearest ways of showing trend in your data. R is extremely good for this type of ... [Read more...]

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Terrain attributes can be derived by elevation values on a small neighbourhood of each DEM point.The major attributes can be calculated from the derivatives of the topographic surface. These derivatives measure the rate of change in elevation in relati... [Read more...]

During the UseR 2011 conference I saw lots of examples of the use of RPanel to create a GUI in R. Yesterday, because I was a bit bored of the work I was doing I started thinking about this and I decided to try this package.My objective was to create ... [Read more...]

This is the last lesson of the R Videotutorial for spatial statistics.It is all about cokriging in gstat. For this lesson I used the meuse dataset, available within gstat, for the references to this dataset take a look at the script.The videotutorial i... [Read more...]

Hi,in these days I'm creating lots and lots of box plot with ggplot2.The look of them is really good and you can change every bit of code so that you can customize the plot completely.Here is the code I'm using with a test data file to try ... [Read more...]

Hi,these days I'm working with soil textural data and one of the key point of these data is the presentation of the results.The best way is a old-school texture triangle!!!Because I like to do all my stuff in R, instead of opening draw software such as... [Read more...]

I received requests for the script used during the tutorial.All the material is available in the main page of the course.However, in order to facilitate the availability of the scripts to all the viewers of this blog I've put the link to donwnload them... [Read more...]

Hello everyone, I’m trying to create a method for calculating the 5 parameters for the 3D anisotropy in an automatic way. Basically I created a loop for analysing the range of the horizontal variogram in every direction and extrapolating the maximum (for the angle p). Then it computes the vertical ... [Read more...]