arb/examples/lcentral.c

/* This file is public domain. Author: Pascal Molin. */

#include <string.h>
#include <math.h>
#include "acb_dirichlet.h"

static int usage(char *argv[])
{
    printf("usage: %s [--quiet] [--prec <bits>] qmin qmax\n", argv[0]);
    return 1;
}

int main(int argc, char *argv[])
{
    int i, out = 1;
    slong prec = 100, digits = 30;
    ulong qmin, qmax, q;
    acb_t s;

    if (argc < 3)
        return usage(argv);

    for (i = 1; i < argc - 2; i++)
    {
        if (!strcmp(argv[i],"--quiet"))
            out = 0;
        else if (!strcmp(argv[i],"--prec"))
        {
            i++;
            prec = atol(argv[i]);
            digits = floor(prec * 0.3);
        }
    }

    if (argc < i + 2)
        return usage(argv);

    qmin = atol(argv[i]);
    qmax = atol(argv[i+1]);

    fflush(stdout);

    acb_init(s);
    acb_one(s);
    acb_div_si(s, s, 2, prec);

    for (q = qmin; q <= qmax; q++)
    {
        ulong k;
        dirichlet_group_t G;
        dirichlet_conrey_t x;
        acb_ptr z;

        if (q % 4 == 2)
            continue;

        dirichlet_group_init(G, q);
        dirichlet_conrey_init(x, G);

        z =  _acb_vec_init(G->phi_q);

        acb_dirichlet_l_vec_hurwitz(z, s, G, prec);

        if (out)
        {
            k = 0;
            dirichlet_conrey_one(x, G);
            while (dirichlet_conrey_next(x, G) >= 0)
            {
                k++;
                if (dirichlet_conrey_conductor(G,x) < q)
                    continue;
                flint_printf("%wu,%wu: ", q, x->n);
                acb_printd(z + k, digits);
                flint_printf("\n");
            }
        }

        _acb_vec_clear(z, G->phi_q);
        dirichlet_conrey_clear(x);
        dirichlet_group_clear(G);
    }
    acb_clear(s);

    flint_cleanup();
    return EXIT_SUCCESS;
}