action_on_flags.cpp

Go to the documentation of this file.

// action_on_flags.cpp
//
// Anton Betten
// May 21, 2016
 
#include "foundations/foundations.h"
#include "group_actions.h"
 
 
using namespace std;
 
 
namespace orbiter {
namespace layer3_group_actions {
namespace induced_actions {
 
 
action_on_flags::action_on_flags()
{
    null();
}
 
action_on_flags::~action_on_flags()
{
    free();
}
 
void action_on_flags::null()
{
    A = NULL;
    type = NULL;
    type_len = 0;
}
 
void action_on_flags::free()
{
    null();
}
 
void action_on_flags::init(actions::action *A, int *type,
        int type_len, int verbose_level)
{
    int f_v = (verbose_level >= 1);
    
    if (f_v) {
        cout << "action_on_flags::init" << endl;
        }
    action_on_flags::A = A;
    action_on_flags::type = type;
    action_on_flags::type_len = type_len;
    if (!A->f_is_linear) {
        cout << "action_on_flags::init the action must be "
                "linear but is not" << endl;
        exit(1);
        }
    n = A->dimension;
    if (A->type_G == matrix_group_t) {
        M = A->G.matrix_grp;
        }
    else {
        actions::action *sub = A->subaction;
        M = sub->G.matrix_grp;
        }
    F = M->GFq;
    if (f_v) {
        cout << "action_on_flags::init n=" << n << " q=" << F->q << endl;
        }
 
    Flag = NEW_OBJECT(geometry::flag);
    Flag->init(n, type, type_len, F, verbose_level);
 
    degree = Flag->N;
    if (f_v) {
        cout << "action_on_flags::init degree = " << degree << endl;
        }
 
    M1 = NEW_int(n * n);
    M2 = NEW_int(n * n);
    if (f_v) {
        cout << "action_on_flags::init done" << endl;
        }
}
 
long int action_on_flags::compute_image(int *Elt, long int i, int verbose_level)
{
    int f_v = (verbose_level >= 1);
    long int h, j;
 
    if (f_v) {
        cout << "action_on_flags::compute_image "
                "i = " << i << endl;
        }
    if (i < 0 || i >= degree) {
        cout << "action_on_flags::compute_image "
                "i = " << i << " out of range" << endl;
        exit(1);
        }
    if (f_v) {
        cout << "Elt=" << endl;
        A->element_print_quick(Elt, cout);
        }
    Flag->unrank(i, M1, 0 /*verbose_level*/);
    if (f_v) {
        cout << "action_on_flags::compute_image M1=" << endl;
        Int_matrix_print(M1, Flag->K, n);
        }
    if (f_v) {
        cout << "action_on_flags::compute_image "
                "before image_of_low_level" << endl;
        }
    for (h = 0; h < Flag->K; h++) {
        A->image_of_low_level(Elt,
                M1 + h * n, M2 + h * n, verbose_level - 1);
        }
    if (f_v) {
        cout << "action_on_flags::compute_image "
                "after image_of_low_level" << endl;
        }
    if (f_v) {
        cout << "action_on_flags::compute_image M2=" << endl;
        Int_matrix_print(M2, Flag->K, n);
        }
    j = Flag->rank(M2, 0 /*verbose_level*/);
 
    if (f_v) {
        cout << "action_on_flags::compute_image "
                << i << " maps to " << j << endl;
        }
    return j;
}
 
 
}}}