contributions of covariates and methods paper: revisions-change of residuals in function of elev and use of lattice package

contributions of covariates and methods paper: revisions - addtional improvements to figures (variograms, residuals etc.)

contribution of covariates and methods: revisions-adding summary of variogram param and accuracy summarized by stations

contribution of covariates and method paper: revisions adding figures of variograms and map of residuals

assessment NEX run 3 part2: adding function to combine shapefiles to create plots of number of stations per tiles and accuracy

assessment NEX run part2: adding plots of number of stations per tiles

assessment NEX run 3 North America with prediction info for training and testing stations

assessment NEX run 3: modifications to analyze results with figures

assessment NEX run part1: debugging extraction of training and testing info function

assessment NEX run part3: major updates to generate stat and fig for specific tiles