root / trunk / libraries / libjni-proj4 / src / mk_cheby.c @ 8667
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#ifndef lint
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static const char SCCSID[]="@(#)mk_cheby.c 4.5 94/03/22 GIE REL"; |
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#endif
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#include <projects.h> |
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static void /* sum coefficients less than res */ |
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eval(projUV **w, int nu, int nv, double res, projUV *resid) { |
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int i, j;
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double ab;
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projUV *s; |
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|
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resid->u = resid->v = 0.;
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for (i = 0; i < nu; ++i) |
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for (s = w[i], j = 0; j < nv; ++j, ++s) { |
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if ((ab = fabs(s->u)) < res)
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resid->u += ab; |
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if ((ab = fabs(s->v)) < res)
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resid->v += ab; |
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} |
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} |
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static Tseries * /* create power series structure */ |
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makeT(int nru, int nrv) { |
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Tseries *T; |
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int i;
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|
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if ((T = (Tseries *)pj_malloc(sizeof(Tseries))) && |
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(T->cu = (struct PW_COEF *)pj_malloc(
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sizeof(struct PW_COEF) * nru)) && |
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(T->cv = (struct PW_COEF *)pj_malloc(
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sizeof(struct PW_COEF) * nrv))) { |
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for (i = 0; i < nru; ++i) |
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T->cu[i].c = 0;
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for (i = 0; i < nrv; ++i) |
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T->cv[i].c = 0;
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return T;
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} else
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return 0; |
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} |
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Tseries * |
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mk_cheby(projUV a, projUV b, double res, projUV *resid, projUV (*func)(projUV),
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int nu, int nv, int power) { |
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int j, i, nru, nrv, *ncu, *ncv;
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Tseries *T; |
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projUV **w; |
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double cutres;
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|
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if (!(w = (projUV **)vector2(nu, nv, sizeof(projUV))) || |
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!(ncu = (int *)vector1(nu + nv, sizeof(int)))) |
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return 0; |
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ncv = ncu + nu; |
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if (!bchgen(a, b, nu, nv, w, func)) {
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projUV *s; |
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double ab, *p;
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|
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/* analyse coefficients and adjust until residual OK */
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cutres = res; |
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for (i = 4; i ; --i) { |
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eval(w, nu, nv, cutres, resid); |
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if (resid->u < res && resid->v < res)
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break;
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cutres *= 0.5; |
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} |
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if (i <= 0) /* warn of too many tries */ |
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resid->u = - resid->u; |
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/* apply cut resolution and set pointers */
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nru = nrv = 0;
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for (j = 0; j < nu; ++j) { |
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ncu[j] = ncv[j] = 0; /* clear column maxes */ |
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for (s = w[j], i = 0; i < nv; ++i, ++s) { |
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if ((ab = fabs(s->u)) < cutres) /* < resolution ? */ |
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s->u = 0.; /* clear coefficient */ |
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else
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ncu[j] = i + 1; /* update column max */ |
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if ((ab = fabs(s->v)) < cutres) /* same for v coef's */ |
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s->v = 0.;
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else
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ncv[j] = i + 1;
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} |
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if (ncu[j]) nru = j + 1; /* update row max */ |
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if (ncv[j]) nrv = j + 1; |
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} |
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if (power) { /* convert to bivariate power series */ |
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if (!bch2bps(a, b, w, nu, nv))
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goto error;
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/* possible change in some row counts, so readjust */
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nru = nrv = 0;
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for (j = 0; j < nu; ++j) { |
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ncu[j] = ncv[j] = 0; /* clear column maxes */ |
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for (s = w[j], i = 0; i < nv; ++i, ++s) { |
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if (s->u)
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ncu[j] = i + 1; /* update column max */ |
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if (s->v)
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ncv[j] = i + 1;
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} |
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if (ncu[j]) nru = j + 1; /* update row max */ |
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if (ncv[j]) nrv = j + 1; |
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} |
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if (T = makeT(nru, nrv)) {
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T->a = a; |
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T->b = b; |
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T->mu = nru - 1;
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T->mv = nrv - 1;
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T->power = 1;
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for (i = 0; i < nru; ++i) /* store coefficient rows for u */ |
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if (T->cu[i].m = ncu[i])
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if ((p = T->cu[i].c =
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(double *)pj_malloc(sizeof(double) * ncu[i]))) |
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for (j = 0; j < ncu[i]; ++j) |
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*p++ = (w[i] + j)->u; |
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else
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goto error;
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for (i = 0; i < nrv; ++i) /* same for v */ |
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if (T->cv[i].m = ncv[i])
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if ((p = T->cv[i].c =
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(double *)pj_malloc(sizeof(double) * ncv[i]))) |
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for (j = 0; j < ncv[i]; ++j) |
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*p++ = (w[i] + j)->v; |
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else
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goto error;
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} |
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} else if (T = makeT(nru, nrv)) { |
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/* else make returned Chebyshev coefficient structure */
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T->mu = nru - 1; /* save row degree */ |
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T->mv = nrv - 1;
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T->a.u = a.u + b.u; /* set argument scaling */
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T->a.v = a.v + b.v; |
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T->b.u = 1. / (b.u - a.u);
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T->b.v = 1. / (b.v - a.v);
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T->power = 0;
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for (i = 0; i < nru; ++i) /* store coefficient rows for u */ |
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if (T->cu[i].m = ncu[i])
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if ((p = T->cu[i].c =
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(double *)pj_malloc(sizeof(double) * ncu[i]))) |
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for (j = 0; j < ncu[i]; ++j) |
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*p++ = (w[i] + j)->u; |
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else
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goto error;
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for (i = 0; i < nrv; ++i) /* same for v */ |
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if (T->cv[i].m = ncv[i])
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if ((p = T->cv[i].c =
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(double *)pj_malloc(sizeof(double) * ncv[i]))) |
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for (j = 0; j < ncv[i]; ++j) |
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*p++ = (w[i] + j)->v; |
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else
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goto error;
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} else
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goto error;
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} |
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goto gohome;
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error:
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if (T) { /* pj_dalloc up possible allocations */ |
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for (i = 0; i <= T->mu; ++i) |
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if (T->cu[i].c)
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pj_dalloc(T->cu[i].c); |
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for (i = 0; i <= T->mv; ++i) |
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if (T->cv[i].c)
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pj_dalloc(T->cv[i].c); |
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pj_dalloc(T); |
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} |
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T = 0;
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gohome:
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freev2((void **) w, nu);
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pj_dalloc(ncu); |
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return T;
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} |