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get_std_center.C

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#include "dyn.h"

#ifndef TOOLBOX

int get_std_center(dyn *b, vector& pos, vector& vel,
                   bool verbose)                        // default = false
{
    int which = 0;

    // See if densities are available and up to date.

    if (find_qmatch(b->get_dyn_story(), "density_center_pos")) {

        if (getrq(b->get_dyn_story(), "density_center_time")
                != b->get_system_time()) {

            if (verbose)
              warning("get_std_center: ignoring out-of-date density center");

        } else {

            // Assume that density_center_vel exists if density_center_pos
            // is OK.

            pos = getvq(b->get_dyn_story(), "density_center_pos");
            vel = getvq(b->get_dyn_story(), "density_center_vel");

            which = 1;
        }
    }

    if (which == 0) {

        if (find_qmatch(b->get_dyn_story(), "mcom_pos")) {

            // Try modified center of mass instead.

            if (getrq(b->get_dyn_story(), "mcom_time")
                    != b->get_system_time()) {

                if (verbose)
                    warning("get_std_center: ignoring out-of-date mcom");

            } else {

                pos = getvq(b->get_dyn_story(), "mcom_pos");
                vel = getvq(b->get_dyn_story(), "mcom_vel");

                which = 2;
            }

        }

        if (which == 0) {

            // Compute the modified center of mass.

            compute_mcom(b, pos, vel);
            which = 2;
        }
    }

    putrq(b->get_dyn_story(), "std_center_time", b->get_system_time());
    putvq(b->get_dyn_story(), "std_center_pos", pos);
    putvq(b->get_dyn_story(), "std_center_vel", vel);

    return which;
}

int get_std_center(dyn *b,
                   bool verbose)                // default = false
{
    vector pos, vel;
    return get_std_center(b, pos, vel, verbose);
}

#else

//-----------------------------------------------------------------------------
//  main  --  driver to use get_std_center() as a tool
//-----------------------------------------------------------------------------

main(int argc, char ** argv)
{
    char  *comment;
    dyn * b;
    bool  c_flag = FALSE;       // if TRUE: a comment given on command line

    check_help();

    extern char *poptarg;
    int c;
    char* param_string = "c:";

    while ((c = pgetopt(argc, argv, param_string)) != -1)
        switch(c) {

            case 'c': c_flag = TRUE;
                      comment = poptarg;
                      break;
            case '?': params_to_usage(cerr, argv[0], param_string);
                      get_help();
                      exit(1);
        }            

    if ((b = get_dyn(cin)) == NULL)
       err_exit("compute_com: No N-body system on standard input");

    while (b) {

        if (c_flag == TRUE)
            b->log_comment(comment);
        b->log_history(argc, argv);

        get_std_center(b, true);

        // Write system to stdout and get next system (if any).

        put_dyn(cout, *b);
        rmtree(b);
        b = get_dyn(cin);
    }
}

#endif

// endof: get_std_center.C

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