GraphEnt: a maximum-entropy program with graphics capabilities

A maximum-entropy formalism aimed at the production of a 'maximally noncomm ittal' map is a standard method in fields of science like radioastronomy, b ut a rare exception in both X-ray crystallography and electron microscopy ( or crystallography). This is rather unfortunate, given the wealth of inform ation that a maximum-entropy map can reveal, especially when the map itself is the end product (for example, low-resolution electron or potential dens ity maps, Patterson functions, deformation maps). The program GraphEnt atte mpts to automate the procedure of calculating maximum-entropy maps, with em phasis on the calculation of difference Patterson functions for macromolecu lar crystallographic problems, while providing a useful graphical output of the current stage of the calculation.