My_Environment

Ubuntu 14.04 LTS Japanese Remix
on VMWare Fusion v8.5.2 (4635224)
on OS X El Captian v10.11.4

GNU bash, version 4.3.11(1)-release

gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4 
(also for g++)
ADDA v.1.3b6

This article is related to ADDA (light scattering simulator based on the discrete dipole approximation).

In iterative.c, I found the following comments:

/* Checkpoint systems saves the current state of the iterative solver to the file. By default (for every iterative

solver) a number of scalars and vectors are saved. The scalars include, among others, inprodR. **There are 3 default
vectors: xvec, rvec, pvec (Avecbuffer is not saved)**. If the iterative solver requires any other scalars or vectors
to describe its state, this information should be specified in structure arrays 'scalars' and 'vectors'.
*/

The Checkpoint systems are prepared with functions named as SaveIterChpoint() and LoadIterChpoint().

If my understanding is correct, the Checkpoint systems are used to stop/resume the calculation. Therefore I think that SaveIterChpoint() stores the coefficients of system of linear equations somewhere as files.