geolib

convert geo coordinates between various systems (WGS84, RD coords (dutch: RijksDriehoek Coordinaten), ...)

Mathematical background

For reference see the PDF article in the documentation/ directory:

Benaderingsformules voor de transformatie tussen RD- en WGS84-kaartcoördinaten

ing. F.H. Schreutelkamp,

Stichting ‘De Koepel’, sterrenwacht ‘Sonnenborgh’ te Utrecht, en

ir. G.L. Strang van Hees,

voormalig universitair docent van de afdeling Geodesie, TU Delft.

API (C library)

xy2ne: RD to WGS84 conversion

int xy2ne(double* n, double* e, double x, double y);

ne2xy: WGS84 to RD conversion

int ne2xy(double* x, double* y, double n, double e);

nddd_str: n to Ndd.ddddd string, length of str is at least 10

char* nddd_str(char* str, double n);

eddd_str: e to Eddd.ddddd string, length of str is at least 11

char* eddd_str(char* str, double e);

ddd_str: n, e to Ndd.ddddd Eddd.ddddd string, length of str is at least 21

char* ddd_str(char* str, double n, double e);

ndmm_str: n to Ndd mm.mmm string, length of str is at least 11

char* ndmm_str(char* str, double n);

edmm_str: e to Eddd mm.mmm string, length of str is at least 12

char* edmm_str(char* str, double e);

dmm_str: n, e to Ndd mm.mmm Eddd mm.mmm string, length of str is at least 23

char* dmm_str(char* str, double n, double e);

ndms_str: n to Ndd mm'ss.ss" string, length of str is at least 14

char* ndms_str(char* str, double n);

edms_str: e to Eddd mm'ss.ss" string, length of str is at least 15

char* edms_str(char* str, double e);

dms_str: n, e to Ndd mm'ss.ss" Eddd mm'ss.ss" string, length of str is at least 29

char* dms_str(char* str, double n, double e);

xxx_str: x to X:xxxxxxm, length of str is at least 10

char* xxx_str(char* str, double x);

yyy_str: y to Y:yyyyyym, length of str is at least 10

char* yyy_str(char* str, double y);

xy_str: x, y to X:xxxxxxm Y:yyyyyym, length of str is at least 20

char* xy_str(char* str, double x, double y);

fopen_kml: opens filename and initializes it for kml ponits

FILE* fopen_kml(char* filename);

fprint_placemark: print coordinates with name and description in kml file

int fprint_placemark(FILE* f, double n, double e, char* name, char* description);

fclose_kml: closes kml file

int fclose_kml(FILE* f);

Design goals / TODO

The intent of this library / code is to develop a geocaching tool for analyzing coordinate-based puzzles where bulk processing / visualizing of coordinates is helpful in finding the desired solutuion.

Example

Find the geocache location which is positioned on the coordinate which matches the Pyuthagorean triplet x^2 + y^2 = z^2 where x, y and z are integer.

TODO

• conversion to JavaScript so this code can run in a web page

• visualize results in Google Maps

• ... unit tests?

• ... etc.

Testing

Test output is currently stored in the file PAIRS.TXT.

Test output is oproduced by running main() in the geolib.c source file.