Fitting a Background Map to Spatial Data

The goal of this work is to provide and explain a wayfrom a printed map to afitted background map of a spatial dataset. Thevariables in this dataset can be from anyfield of interest, but there have to be twodimensional coordinates for each observation.One of several implemented transformation types hasto be chosen now. Furthermorewe have to identify reference points on the map andselect reference points from the data.which later should have approximately the samecoordinates and are used for estimatingthe transformation parameters. The process of fittingthe background map is supposed to be iterative, sothat in eachstep new reference points could be added or wrongreference points could be deleted.The presented source code is available in the Rpackage DASplusR.