howtos/command_line_output.md

+# Command Line Output
+
+Command-Line Output of SHEMAT-Suite contains, among other things,
+information about the parameters that were read in by the program, the
+memory used, and the iteration step of the solver. How much of this
+information is displayed depends on the keyword `# linfo` in the
+[Input File](release/tutorial/input_file).
+
+## Table of Contents ##
+
+[[_TOC_]]
+
+# Memory
+
+Information about the memory (found around line 100 of the command line
+output) looks like this:
+
+```
+[I] : memory:     362.763 MByte data
+```
+
+The displayed number of MByte is calculated in the following way: The
+double precision variable `memory` is defined in the module
+`forward/mode_genrl.f90`. In array allocation routines like
+`forward/alloc_arrays.f90`, `forward/alloc_data.f90`,
+`simul/alloc_simul.f90` the number of entries of each allocated array is
+added to `memory`.
+
+In `forward/forward_init.f90` memory is manipulated as follows:
+
+```
+memory = memory*8/1024/1024
+```
+
+and written to the command-line output. The `8` is based on the
+assumption that each entry of an array takes up 8 bytes of memory space
+(like double-precision reals do). The two divisions by `1024` scale the
+number to `MB`.
+
+Finally `memory` is reduced in deallocation routines, like
+`forward/dealloc_arrays.f90` and `simul/read_split_sm.f90`.