Section 25.2.1.2.1. General program structure and data flow

The current package includes 44 Fortran programs and one C subroutine, with the C subroutine used only to provide an interface between the Fortran programs and standard X-Window graphics-library routines. All programs communicate only through files with a simple common format. For the major programs, memory is allocated from a single large one-dimensional array which gets partitioned as required for each problem at run time. This greatly simplifies redimensioning if needed for very large problems, since at most only two lines of code need to be changed. All source code is provided, along with compilation procedures or shell scripts appropriate for most workstations, including Silicon Graphics, Sun, IBM R6000, ESV and DEC Alpha AXP (both OSF and OpenVMS). A flow chart illustrating the major programs and data flow for common phasing procedures is given in Fig. 25.2.1.1.

Figure 25.2.1.1| top | pdf | Flow chart for the major phasing path encompassing native and derivative scaling, heavy-atom-based phasing, solvent flattening, negative-density truncation, and phase combination. Boxed entries represent programs while lines represent files. Optional paths for noncrystallographic symmetry averaging and phase extension are included by considering the additional programs offset from the main path by dashed lines.