/********** Copyright 1990 Regents of the University of California. All rights reserved. Author: 1985 Wayne A. Christopher, U. C. Berkeley CAD Group **********/ #include #include #include #include #include #include #include "points.h" /* Returns the minimum and maximum values of a dvec. Returns a pointer * to static data. If real is TRUE look at the real parts, otherwise * the imag parts. */ double * ft_minmax(struct dvec *v, bool real) { static double res[2]; register int i; double d; res[0] = HUGE; res[1] = - res[0]; for (i = 0; i < v->v_length; i++) { if (isreal(v)) d = v->v_realdata[i]; else if (real) d = realpart(&v->v_compdata[i]); else d = imagpart(&v->v_compdata[i]); if (d < res[0]) res[0] = d; if (d > res[1]) res[1] = d; } return (res); } /* Figure out where a point should go, given the limits of the plotting * area and the type of scale (log or linear). */ int ft_findpoint(double pt, double *lims, int maxp, int minp, bool islog) { double tl, th; if (pt < lims[0]) pt = lims[0]; if (pt > lims[1]) pt = lims[1]; if (islog) { tl = mylog10(lims[0]); th = mylog10(lims[1]); return (int)(((mylog10(pt) - tl) / (th - tl)) * (maxp - minp) + minp); } else { return (int)(((pt - lims[0]) / (lims[1] - lims[0])) * (maxp - minp) + minp); } } /* Will report the minimum and maximum in "reflection coefficient" space */ double * ft_SMITHminmax(struct dvec *v, bool yval) { static double res[2]; register int i; double d, d2; res[0] = HUGE; res[1] = - res[0]; for (i = 0; i < v->v_length; i++) { if (isreal(v)) SMITH_tfm( v->v_realdata[i], 0.0, &d, &d2 ); else SMITH_tfm( realpart(&v->v_compdata[i]), imagpart(&v->v_compdata[i]), &d, &d2 ); /* Are we are looking for min/max X or Y ralue */ if( yval ) d = d2; if (d < res[0]) res[0] = d; if (d > res[1]) res[1] = d; } return (res); } int SMITH_tfm(double re, double im, double *x, double *y) { double dnom; dnom = (re + 1) * (re + 1) + im * im; *x = (re * re + im * im - 1) / dnom; *y = 2 * im / dnom; return 0; }