std::map, pointer to map key value, is this possible?

Section 23.1.2#8 (associative container requirements): The insert members shall not affect the validity of iterators and references to the container, and the erase members shall invalidate only iterators and references to the erased elements. So yes storing pointers to data members of a map element is guaranteed to be valid, unless you remove that element.

Polygon area calculation using Latitude and Longitude generated from Cartesian space and a world file

I checked on internet for various polygon area formulas(or code) but did not find any one good or easy to implement. Now I have written the code snippet to calculate area of a polygon drawn on earth surface. The polygon can have n vertices with each vertex has having its own latitude longitude. Few Important … Read more

Plot only on continent in matplotlib

There’s method in matplotlib.basemap: is_land(xpt, ypt) It returns True if the given x,y point (in projection coordinates) is over land, False otherwise. The definition of land is based upon the GSHHS coastline polygons associated with the class instance. Points over lakes inside land regions are not counted as land points. For more information, see here.