Initial revision

lang/cem/libcc/math/hypot.c

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+/*
+ * (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ * See the copyright notice in the ACK home directory, in the file "Copyright".
+ *
+ * Author: Ceriel J.H. Jacobs
+ */
+
+/* $Header$ */
+
+double
+hypot(x,y)
+	double x,y;
+{
+	/*	Computes sqrt(x*x+y*y), avoiding overflow */
+
+	extern double sqrt();
+
+	if (x < 0) x = -x;
+	if (y < 0) y = -y;
+	if (x > y) {
+		double t = y;
+		y = x;
+		x = t;
+	}
+	/* sqrt(x*x+y*y) = sqrt(y*y*(x*x/(y*y)+1.0)) = y*sqrt(x*x/(y*y)+1.0) */
+	x /= y;
+	return y*sqrt(x*x+1.0);
+}
+
+struct complex {
+	double r,i;
+};
+
+double
+cabs(p_compl)
+	struct complex p_compl;
+{
+	return hypot(p_compl.r, p_compl.i);
+}