How to make more maps

In practice, maps like those presented on this website can be built by using the FeedbackTS package of the R statistical software presented in Soubeyrand et al (2014), and additional R functions allowing to generate google maps from geo-referenced data (e.g. the plotGoogleMaps() function). Maps are made based on analysis of daily rainfall data. Series of about 100 years of data are recommended for the time series analyses involved in calculating the feedback indices.

The FeedbackTS package

The package enables analyses of fragmented time directionality (and feedback by extension) in time series. Tools provided by the package allow the analysis of feedback for a single time series and for a set of time series collected across a spatial domain.

  • - The feedback.stat() function computes, from a rainfall time series corresponding to a given weather station, temporal averages of after-before differences around key days (i.e. dmpiv.whole, dmpiv.part1 and dmpiv.part2) and differences in temporal averages around a turning point in time (i.e. dmpiv.change).
  • - The feedback.test() function tests whether a rainfall time series corresponding to a given weather station presents fragmented time directionality or a change in this directionality. It provides p-values (i.e. pval.dmpiv and for statistical tests.
  • - The krige() function performs variogram analysis and kriging prediction. It was used to draw contour lines.

The R tools to produce google maps

  • - The functions contourLines() from the grDevices package, ContourLines2SLDF() from the maptools package, and plotGoogleMaps() from the plotGoogleMaps package can be used to draw contour lines on google maps.
  • - The function plotGoogleMaps() can also be used to draw pins for weather stations and associated data on google maps.

If you make maps of other locations, we will be happy to post them on this website. Please let us know!