This repository consists of the source code used to estimate the centre of the administrative area of Poland in article „Wyznaczamy środek Polski” (published in Delta monthly, January 2018).
The source code may be used to calculate centre of mass of various areas on the ellipsoid of reference, provided the accurate geodesic data are available.
- C++ compiler with support for C++ 2011 standard
- installed and configured MPI environment (OpenMPI, MPICH or similar)
- installed GeographicLib and shapefile libraries
make
To reproduce results from the article, “Państwo.*” files included in data available on the website of Państwowy Rejestr Granic [http://www.gugik.gov.pl/pzgik/dane-bez-oplat/dane-z-panstwowego-rejestru-granic-i-powierzchni-jednostek-podzialow-terytorialnych-kraju-prg] have to be downloaded and extracted to a suitable directory. Various versions of these data are also available from [http://srodekpolski.pl].
USAGE: ./srodek N path_to_shapefile [ object_index ]
Program needs two command-line arguments: N, which is the number of grid cells in one dimension, and a path to the shapefile. Total number of grid points (labeled M in the article) will be equal to M = N2.
Optionally, if multi-object shapefile is given, additional third parameter should denote an index of the object in the shapefile. If the third parameter is not given, the first object in the file will be read.
IMPORTANT: the current version of the program works only with the most recent dataset, consisting of simple latitude and longitude values. To work with older datasets represented in Transverse Mercator projection, use the version from transverse-mercator branch instead.
(for the original data set used for publication)
./srodek 10 Państwo
10 312679.529 52.1143376218 19.4236714921 -4083.578 52°06′51.62″ 19°25′25.22″
Subsequent values denote:
- chosen value of N
- administrative area of Poland (m2)
- estimated latitude of the centre (°)
- estimated longitude of the centre (°)
- estimated altitude of the centre relative to the ellipsoid of reference (m)
- latitude (repeated) in degrees-minutes-seconds
- longitude (repeated) in degrees-minutes-seconds