/** change grid to /g/, returns TRUE if new grid size differs from old */
void
Canvas::grid ( Grid *g )
{
m.grid = g;
if ( ! g )
return;
m.vp = &g->viewport;
char *s = m.vp->dump();
DMESSAGE( "viewport: %s", s );
free( s );
m.ruler_drawn = false;
resize_grid();
update_mapping();
m.shape = m.grid->draw_shape();
/* connect signals */
/* FIXME: what happens when we do this twice? */
g->signal_events_change.connect( mem_fun( this, &Canvas::handle_event_change ) );
g->signal_settings_change.connect( signal_settings_change.make_slot() );
signal_draw();
signal_settings_change();
}
/** adjust vertical zoom (* n) */
void
Canvas::v_zoom ( float n )
{
m.vp->h = max( 1, min( (int)(m.vp->h * n), m.maxh ) );
resize_grid();
song.set_dirty();
}
/** adjust horizontal zoom (* n) */
void
Canvas::h_zoom ( float n )
{
m.vp->w = max( 32, min( (int)(m.vp->w * n), 256 ) );
resize_grid();
song.set_dirty();
}
void
Canvas::v_zoom_fit ( void )
{
if ( ! m.grid )
return;
changed_mapping();
m.vp->h = m.maxh;
m.vp->y = 0;
resize_grid();
song.set_dirty();
}
static void
phosphor_reshape (Display *dpy, Window window, void *closure,
unsigned int w, unsigned int h)
{
p_state *state = (p_state *) closure;
resize_grid (state);
# if defined(HAVE_FORKPTY) && defined(TIOCSWINSZ)
if (state->pid)
{
/* Tell the sub-process that the screen size has changed. */
struct winsize ws;
ws.ws_row = state->grid_height - 1;
ws.ws_col = state->grid_width - 2;
ws.ws_xpixel = state->xgwa.width;
ws.ws_ypixel = state->xgwa.height;
ioctl (fileno (state->pipe), TIOCSWINSZ, &ws);
kill (state->pid, SIGWINCH);
}
# endif /* HAVE_FORKPTY && TIOCSWINSZ */
}
int
gsl_monte_vegas_integrate (gsl_monte_function * f,
double xl[], double xu[],
size_t dim, size_t calls,
gsl_rng * r,
gsl_monte_vegas_state * state,
double *result, double *abserr)
{
double cum_int, cum_sig;
size_t i, k, it;
if (dim != state->dim)
{
GSL_ERROR ("number of dimensions must match allocated size", GSL_EINVAL);
}
for (i = 0; i < dim; i++)
{
if (xu[i] <= xl[i])
{
GSL_ERROR ("xu must be greater than xl", GSL_EINVAL);
}
if (xu[i] - xl[i] > GSL_DBL_MAX)
{
GSL_ERROR ("Range of integration is too large, please rescale",
GSL_EINVAL);
}
}
if (state->stage == 0)
{
init_grid (state, xl, xu, dim);
if (state->verbose >= 0)
{
print_lim (state, xl, xu, dim);
}
}
if (state->stage <= 1)
{
state->wtd_int_sum = 0;
state->sum_wgts = 0;
state->chi_sum = 0;
state->it_num = 1;
state->samples = 0;
state->chisq = 0;
}
if (state->stage <= 2)
{
unsigned int bins = state->bins_max;
unsigned int boxes = 1;
if (state->mode != GSL_VEGAS_MODE_IMPORTANCE_ONLY)
{
/* shooting for 2 calls/box */
boxes = floor (pow (calls / 2.0, 1.0 / dim));
state->mode = GSL_VEGAS_MODE_IMPORTANCE;
if (2 * boxes >= state->bins_max)
{
/* if bins/box < 2 */
int box_per_bin = GSL_MAX (boxes / state->bins_max, 1);
bins = GSL_MIN(boxes / box_per_bin, state->bins_max);
boxes = box_per_bin * bins;
state->mode = GSL_VEGAS_MODE_STRATIFIED;
}
}
{
double tot_boxes = gsl_pow_int ((double) boxes, dim);
state->calls_per_box = GSL_MAX (calls / tot_boxes, 2);
calls = state->calls_per_box * tot_boxes;
}
/* total volume of x-space/(avg num of calls/bin) */
state->jac = state->vol * pow ((double) bins, (double) dim) / calls;
state->boxes = boxes;
/* If the number of bins changes from the previous invocation, bins
are expanded or contracted accordingly, while preserving bin
density */
if (bins != state->bins)
{
resize_grid (state, bins);
if (state->verbose > 1)
{
print_grid (state, dim);
}
}
if (state->verbose >= 0)
{
print_head (state,
dim, calls, state->it_num, state->bins, state->boxes);
}
}
state->it_start = state->it_num;
cum_int = 0.0;
cum_sig = 0.0;
for (it = 0; it < state->iterations; it++)
{
double intgrl = 0.0, intgrl_sq = 0.0;
double tss = 0.0;
double wgt, var, sig;
size_t calls_per_box = state->calls_per_box;
double jacbin = state->jac;
double *x = state->x;
coord *bin = state->bin;
state->it_num = state->it_start + it;
reset_grid_values (state);
init_box_coord (state, state->box);
do
{
volatile double m = 0, q = 0;
double f_sq_sum = 0.0;
for (k = 0; k < calls_per_box; k++)
{
volatile double fval;
double bin_vol;
random_point (x, bin, &bin_vol, state->box, xl, xu, state, r);
fval = jacbin * bin_vol * GSL_MONTE_FN_EVAL (f, x);
/* recurrence for mean and variance (sum of squares) */
{
double d = fval - m;
m += d / (k + 1.0);
q += d * d * (k / (k + 1.0));
}
if (state->mode != GSL_VEGAS_MODE_STRATIFIED)
{
double f_sq = fval * fval;
accumulate_distribution (state, bin, f_sq);
}
}
intgrl += m * calls_per_box;
f_sq_sum = q * calls_per_box;
tss += f_sq_sum;
if (state->mode == GSL_VEGAS_MODE_STRATIFIED)
{
accumulate_distribution (state, bin, f_sq_sum);
}
}
while (change_box_coord (state, state->box));
/* Compute final results for this iteration */
var = tss / (calls_per_box - 1.0) ;
if (var > 0)
{
wgt = 1.0 / var;
}
else if (state->sum_wgts > 0)
{
wgt = state->sum_wgts / state->samples;
}
else
{
wgt = 0.0;
}
intgrl_sq = intgrl * intgrl;
sig = sqrt (var);
state->result = intgrl;
state->sigma = sig;
if (wgt > 0.0)
{
double sum_wgts = state->sum_wgts;
double wtd_int_sum = state->wtd_int_sum;
double m = (sum_wgts > 0) ? (wtd_int_sum / sum_wgts) : 0;
double q = intgrl - m;
state->samples++ ;
state->sum_wgts += wgt;
state->wtd_int_sum += intgrl * wgt;
state->chi_sum += intgrl_sq * wgt;
cum_int = state->wtd_int_sum / state->sum_wgts;
cum_sig = sqrt (1 / state->sum_wgts);
#if USE_ORIGINAL_CHISQ_FORMULA
/* This is the chisq formula from the original Lepage paper. It
computes the variance from <x^2> - <x>^2 and can suffer from
catastrophic cancellations, e.g. returning negative chisq. */
if (state->samples > 1)
{
state->chisq = (state->chi_sum - state->wtd_int_sum * cum_int) /
(state->samples - 1.0);
}
#else
/* The new formula below computes exactly the same quantity as above
but using a stable recurrence */
if (state->samples == 1) {
state->chisq = 0;
} else {
state->chisq *= (state->samples - 2.0);
state->chisq += (wgt / (1 + (wgt / sum_wgts))) * q * q;
state->chisq /= (state->samples - 1.0);
}
#endif
}
else
{
cum_int += (intgrl - cum_int) / (it + 1.0);
cum_sig = 0.0;
}
if (state->verbose >= 0)
{
print_res (state,
state->it_num, intgrl, sig, cum_int, cum_sig,
state->chisq);
if (it + 1 == state->iterations && state->verbose > 0)
{
print_grid (state, dim);
}
}
if (state->verbose > 1)
{
print_dist (state, dim);
}
refine_grid (state);
if (state->verbose > 1)
{
print_grid (state, dim);
}
}
/* By setting stage to 1 further calls will generate independent
estimates based on the same grid, although it may be rebinned. */
state->stage = 1;
*result = cum_int;
*abserr = cum_sig;
return GSL_SUCCESS;
}
