In my my last post I described how to produce a multivariate choropleth map with R. Now I will show …Continuar leyendo » [Read more...]

This is the first post of a short series to show some code I have learnt to produce maps with …Continuar leyendo » [Read more...]

  Some days ago the journal Renewable Energy published my last paper “Cost of energy and mutual shadows in a …Continuar leyendo » [Read more...]

Some time ago I posted a question in stackoverflow to learn how to produce a multipage SVG file. This is …Continuar leyendo » [Read more...]

The function slopeAspect from raster provides the vector field (gradient) from a scalar field stored in a RasterLayer object. The magnitude (slope) and direction (aspect) of the vector field is usually displayed with a set of arrows (e.g. quiver in Matlab). rasterVis includes now a method, vectorplot, to calculate ... [Read more...]

PC-Axis is a software family consisting of a number of programs for the Windows and Internet environment used to present statistical information. It is used by national and international institutions to publish statistical data. Programs in the PC-Axis family use a particular data file format (see the full PX-Axis data ... [Read more...]

Emilio Torres Manzanera has just announced the 1st Data Analysis Contest Using R: “Nestoria (http://www.nestoria.com/) is a specialized web search engine platform in house prices. Nestoria and Lokku Labs aim to improve the understanding of the public of the value of its databases. The company aims to ... [Read more...]

The raster package defines classes and methods for spatial raster data access and manipulation. The new rasterVis package complements raster providing a set of methods for enhanced visualization and interaction. It is now at CRAN. Several examples can ... [Read more...]

The Satellite Application Facility on Climate Monitoring (CMSAF) generates, archives and distributes widely recognised high-quality satellite-derived products and services relevant for climate monitoring in operational mode. The data is freely accesible here after a registration process. I have ask them for several files with monthly averages of global solar radiation ... [Read more...]

The version 0.24 of solaR is at CRAN and R-Forge. Some days before the 0.23 version was uploaded, but I had to make a quick fix to readMAPA: the url of http://www.mapa.es/siar has been changed to http://www.marm.es/siar. Moreover, this function has been renamed to ... [Read more...]

Recently I found a post at FlowingData with a detailed tutorial to map connections with great circles with R. The tutorial of FlowingData is excellent, but I feel more comfortable with the sp classes and methods, and with the lattice and latticeExtra packages. Besides, I want to use the free ... [Read more...]

Recently, Kevin Ummel gave a short conference about his PhD research at the Sustainable futures – Tyndall Centre researchers’ international conference. His work, named “Optimizing worldwide deployment of wind and solar power technologies via a high resolution, linear programming model”, is built with R. He is using the solaR package for ... [Read more...]

The solar irradiance incident outside the earth’s atmosphere is called the extraterrestial or extra-atmospheric irradiance. It is derived from the solar constant only with geometric equations. It can be easily calculated with the calcSol function of the solaR package. With this post I will show an example with some ... [Read more...]

What are the alpha shapes?: “The concept of alpha shapes formalizes the intuitive notion of “shape” for spatial point set data, which occurs frequently in the computational sciences. An alpha shape is a concrete geometric object that is uniquely defined for a particular point set.[...] Alpha shapes are generalizations of ... [Read more...]

The Atmospheric Science Data Center (ASDC) at NASA Langley Research Center offers several data sources. For example, it is possible to download a text file with the 22-year (July 1983 – June 2005) monthly and annual average of global horizontal irradiation. nasafile [Read more...]

A violin plot is a combination of a boxplot and a kernel density plot. Lattice includes the panel.violin function for this graphical tool. This example draws a violin and a boxplot together. First, let’s download some solar radiation data from the NASA webpage: nasafile [Read more...]

The version 0.22 of solaR includes a new method, mergesolaR. It is designed to merge daily time series of several solaR objects. For example, we can obtain the daily irradiation of the whole set of meteorological stations of Madrid (Spain) and use this information to calculate the productivity of a grid ... [Read more...]

The version 0.22 of solaR is now available at CRAN. Besides, solaR is now registered at R-Forge. A new mergesolaR method has been defined for merging solaR objects. The calculation of the sunset time has been improved. The voltage dependency of the efficiency curve of the inverter is now included in ... [Read more...]

In lattice, there is a function called splom for the display of scatter plot matrices. For large datasets, the panel.hexbinplot from the hexbin package is a better option than the default panel. As an example, let’s use some meteorological data from MAPA-SIAR: library(solaR) library(hexbin) aranjuez [Read more...]

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