R package SPEDInstabR: Estimation of the Relative Importance of Factors Affecting Species Distribution Based on Stability Concept. From output files obtained from the software ModestR, the relative contribution of factors to explain species distribution is depicted using several plots. A global geographic raster file for each environmental variable may be also obtained with the mean relative contribution, considering all species present in each raster cell, of the factor to explain species distribution. Finally, for each variable it is also possible to compare the frequencies of any variable obtained in the cells where the species is present with the frequencies of the same variable in the cells of the extent.