| 314 |
|
posgradient(gv, da, hp) /* compute position gradient */ |
| 315 |
|
FVECT gv; |
| 316 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 317 |
< |
AMBHEMI *hp; |
| 317 |
> |
register AMBHEMI *hp; |
| 318 |
|
{ |
| 319 |
|
register int i, j; |
| 320 |
< |
double b, d; |
| 320 |
> |
double nextsine, lastsine, b, d; |
| 321 |
|
double mag0, mag1; |
| 322 |
|
double phi, cosp, sinp, xd, yd; |
| 323 |
|
register AMBSAMP *dp; |
| 326 |
|
for (j = 0; j < hp->np; j++) { |
| 327 |
|
dp = da + j; |
| 328 |
|
mag0 = mag1 = 0.0; |
| 329 |
+ |
lastsine = 0.0; |
| 330 |
|
for (i = 0; i < hp->nt; i++) { |
| 331 |
|
#ifdef DEBUG |
| 332 |
|
if (dp->t != i || dp->p != j) |
| 337 |
|
if (i > 0) { |
| 338 |
|
d = dp[-hp->np].r; |
| 339 |
|
if (dp[0].r > d) d = dp[0].r; |
| 340 |
< |
d *= 1.0 - (double)i/hp->nt; /* cos(t)^2 */ |
| 340 |
> |
/* sin(t)*cos(t)^2 */ |
| 341 |
> |
d *= lastsine * (1.0 - (double)i/hp->nt); |
| 342 |
|
mag0 += d*(b - bright(dp[-hp->np].v)); |
| 343 |
|
} |
| 344 |
+ |
nextsine = sqrt((double)(i+1)/hp->nt); |
| 345 |
|
if (j > 0) { |
| 346 |
|
d = dp[-1].r; |
| 347 |
|
if (dp[0].r > d) d = dp[0].r; |
| 348 |
< |
mag1 += d*(b - bright(dp[-1].v)); |
| 348 |
> |
mag1 += d * (nextsine - lastsine) * |
| 349 |
> |
(b - bright(dp[-1].v)); |
| 350 |
|
} else { |
| 351 |
|
d = dp[hp->np-1].r; |
| 352 |
|
if (dp[0].r > d) d = dp[0].r; |
| 353 |
< |
mag1 += d*(b - bright(dp[hp->np-1].v)); |
| 353 |
> |
mag1 += d * (nextsine - lastsine) * |
| 354 |
> |
(b - bright(dp[hp->np-1].v)); |
| 355 |
|
} |
| 356 |
|
dp += hp->np; |
| 357 |
+ |
lastsine = nextsine; |
| 358 |
|
} |
| 359 |
< |
if (hp->nt > 1) { |
| 354 |
< |
mag0 /= (double)hp->np; |
| 355 |
< |
mag1 /= (double)hp->nt; |
| 356 |
< |
} |
| 359 |
> |
mag0 *= 2.0*PI / hp->np; |
| 360 |
|
phi = 2.0*PI * (double)j/hp->np; |
| 361 |
|
cosp = cos(phi); sinp = sin(phi); |
| 362 |
|
xd += mag0*cosp - mag1*sinp; |
| 370 |
|
dirgradient(gv, da, hp) /* compute direction gradient */ |
| 371 |
|
FVECT gv; |
| 372 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 373 |
< |
AMBHEMI *hp; |
| 373 |
> |
register AMBHEMI *hp; |
| 374 |
|
{ |
| 375 |
|
register int i, j; |
| 376 |
|
double mag; |
| 387 |
|
error(CONSISTENCY, |
| 388 |
|
"division order in dirgradient"); |
| 389 |
|
#endif |
| 390 |
< |
mag += sqrt((i+.5)/hp->nt)*bright(dp->v); /* sin(t) */ |
| 390 |
> |
/* tan(t) */ |
| 391 |
> |
mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0); |
| 392 |
|
dp += hp->np; |
| 393 |
|
} |
| 394 |
|
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
| 396 |
|
yd += mag * sin(phi); |
| 397 |
|
} |
| 398 |
|
for (i = 0; i < 3; i++) |
| 399 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])*PI/(hp->nt*hp->np); |
| 399 |
> |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/(hp->nt*hp->np); |
| 400 |
|
} |
