diff options
Diffstat (limited to 'src/mk_cheby.cpp')
| -rw-r--r-- | src/mk_cheby.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/mk_cheby.cpp b/src/mk_cheby.cpp new file mode 100644 index 00000000..a2f90bef --- /dev/null +++ b/src/mk_cheby.cpp @@ -0,0 +1,192 @@ +#include "projects.h" +static void /* sum coefficients less than res */ +eval(projUV **w, int nu, int nv, double res, projUV *resid) { + int i, j; + double ab; + projUV *s; + + resid->u = resid->v = 0.; + for (i = 0; i < nu; ++i) { + s = w[i]; + for (j = 0; j < nv; ++j) { + if ((ab = fabs(s->u)) < res) + resid->u += ab; + if ((ab = fabs(s->v)) < res) + resid->v += ab; + ++s; + } + } +} +static Tseries * /* create power series structure */ +makeT(int nru, int nrv) { + Tseries *T; + int i; + + if (!(T = (Tseries *)pj_malloc(sizeof(Tseries)))) + return 0; + if (!(T->cu = (struct PW_COEF *)pj_malloc(sizeof(struct PW_COEF) * nru))) { + pj_dalloc(T); + return 0; + } + if (!(T->cv = (struct PW_COEF *)pj_malloc(sizeof(struct PW_COEF) * nrv))) { + pj_dalloc(T->cu); + pj_dalloc(T); + return 0; + } + + for (i = 0; i < nru; ++i) + T->cu[i].c = 0; + for (i = 0; i < nrv; ++i) + T->cv[i].c = 0; + return T; +} +Tseries * +mk_cheby(projUV a, projUV b, double res, projUV *resid, projUV (*func)(projUV), + int nu, int nv, int power) { + int j, i, nru, nrv, *ncu, *ncv; + Tseries *T = NULL; + projUV **w; + double cutres; + + if (!(w = (projUV **)vector2(nu, nv, sizeof(projUV)))) + return 0; + if (!(ncu = (int *)vector1(nu + nv, sizeof(int)))) { + freev2((void **)w, nu); + return 0; + } + ncv = ncu + nu; + if (!bchgen(a, b, nu, nv, w, func)) { + projUV *s; + double ab, *p; + + /* analyse coefficients and adjust until residual OK */ + cutres = res; + for (i = 4; i ; --i) { + eval(w, nu, nv, cutres, resid); + if (resid->u < res && resid->v < res) + break; + cutres *= 0.5; + } + if (i <= 0) /* warn of too many tries */ + resid->u = - resid->u; + /* apply cut resolution and set pointers */ + nru = nrv = 0; + for (j = 0; j < nu; ++j) { + ncu[j] = ncv[j] = 0; /* clear column maxes */ + s = w[j]; + for (i = 0; i < nv; ++i) { + if ((ab = fabs(s->u)) < cutres) /* < resolution ? */ + s->u = 0.; /* clear coefficient */ + else + ncu[j] = i + 1; /* update column max */ + if ((ab = fabs(s->v)) < cutres) /* same for v coef's */ + s->v = 0.; + else + ncv[j] = i + 1; + ++s; + } + if (ncu[j]) nru = j + 1; /* update row max */ + if (ncv[j]) nrv = j + 1; + } + if (power) { /* convert to bivariate power series */ + if (!bch2bps(a, b, w, nu, nv)) + goto error; + /* possible change in some row counts, so readjust */ + nru = nrv = 0; + for (j = 0; j < nu; ++j) { + ncu[j] = ncv[j] = 0; /* clear column maxes */ + s = w[j]; + for (i = 0; i < nv; ++i) { + if (s->u != 0.0) + ncu[j] = i + 1; /* update column max */ + if (s->v != 0.0) + ncv[j] = i + 1; + ++s; + } + if (ncu[j]) nru = j + 1; /* update row max */ + if (ncv[j]) nrv = j + 1; + } + if ((T = makeT(nru, nrv)) != NULL ) { + T->a = a; + T->b = b; + T->mu = nru - 1; + T->mv = nrv - 1; + T->power = 1; + for (i = 0; i < nru; ++i) /* store coefficient rows for u */ + { + if ((T->cu[i].m = ncu[i]) != 0) + { + if ((p = T->cu[i].c = + (double *)pj_malloc(sizeof(double) * ncu[i]))) + for (j = 0; j < ncu[i]; ++j) + *p++ = (w[i] + j)->u; + else + goto error; + } + } + for (i = 0; i < nrv; ++i) /* same for v */ + { + if ((T->cv[i].m = ncv[i]) != 0) + { + if ((p = T->cv[i].c = + (double *)pj_malloc(sizeof(double) * ncv[i]))) + for (j = 0; j < ncv[i]; ++j) + *p++ = (w[i] + j)->v; + else + goto error; + } + } + } + } else if ((T = makeT(nru, nrv)) != NULL) { + /* else make returned Chebyshev coefficient structure */ + T->mu = nru - 1; /* save row degree */ + T->mv = nrv - 1; + T->a.u = a.u + b.u; /* set argument scaling */ + T->a.v = a.v + b.v; + T->b.u = 1. / (b.u - a.u); + T->b.v = 1. / (b.v - a.v); + T->power = 0; + for (i = 0; i < nru; ++i) /* store coefficient rows for u */ + { + if ((T->cu[i].m = ncu[i]) != 0) + { + if ((p = T->cu[i].c = + (double *)pj_malloc(sizeof(double) * ncu[i]))) + for (j = 0; j < ncu[i]; ++j) + *p++ = (w[i] + j)->u; + else + goto error; + } + } + for (i = 0; i < nrv; ++i) /* same for v */ + { + if ((T->cv[i].m = ncv[i]) != 0) + { + if ((p = T->cv[i].c = + (double *)pj_malloc(sizeof(double) * ncv[i]))) + for (j = 0; j < ncv[i]; ++j) + *p++ = (w[i] + j)->v; + else + goto error; + } + } + } else + goto error; + } + goto gohome; + error: + if (T) { /* pj_dalloc up possible allocations */ + for (i = 0; i <= T->mu; ++i) + if (T->cu[i].c) + pj_dalloc(T->cu[i].c); + for (i = 0; i <= T->mv; ++i) + if (T->cv[i].c) + pj_dalloc(T->cv[i].c); + pj_dalloc(T); + } + T = 0; + gohome: + freev2((void **) w, nu); + pj_dalloc(ncu); + return T; +} |