R package 'pgeo'

Purpose

This R package contains functions related to broadly "geographical" topics, as opposed to general functions (which are in the package pascal) and biodiversity- related function (which are in the package pdiv)

Groups of functions

Interconversion of WGS-84 and Swiss Grid

These functions convert coordinates between WGS-84 (latitude/longitude) and the Swiss Grid (X:northing/Y:easting). The conversion is approximate with an accuracy of a few meters, based on equations provided by SwissTopo. These functions return the converted coordinates.

• WGStoCH(lat, lon)
• WGStoCHE(lat, lon = NULL)
• WGStoCHN(lat, lon = NULL)
• CHtoWGS(N, E = NULL)
• CHtoWGSlat(N, E = NULL)
• CHtoWGSlon(N, E = NULL)

Interconversion of MODIS (line,sample) and Swiss Grid

These functions converts MODIS line/sample coordinates (250, 500 or 1000m pixel size) from tile H18V04 to Swiss Grid coordinates in meters and vice versa. The accuracy of the conversion is within a few meters.

• modisIJtoCH(I, J = NULL, grid = 250)
• CHtomodisIJ(N, E = NULL, grid = 250)

Conversion from delta-permilles to atom-percent

Often, one needs to convert delta-permil data from isotope-ratio mass spectrometry into atom-percent, i.e. the percentage (or fraction) an isotopes makes up of a given element. This is crucial for mass balance calculations, since delta-values are not proportional to the extent of labelling. The function provided has built-in R data for reference material for several isotopes, but the R can also be provided.

• delta.to.atpct(delta, R = NULL, isotope = "N15", fraction = FALSE)

Installation

• download the ready-built package from the pkgs directory
• use install_github:
  library(devtools)
install_github("pascal-niklaus/pgeo/pgeo")