1 files changed, 46 insertions, 0 deletions
diff --git a/src/zpoly1.cpp b/src/zpoly1.cpp
new file mode 100644
index 00000000..bacb62ce
--- /dev/null
+++ b/src/zpoly1.cpp
@@ -0,0 +1,46 @@
+/* evaluate complex polynomial */
+#include "projects.h"
+/* note: coefficients are always from C_1 to C_n
+**	i.e. C_0 == (0., 0)
+**	n should always be >= 1 though no checks are made
+*/
+	COMPLEX
+pj_zpoly1(COMPLEX z, const COMPLEX *C, int n) {
+	COMPLEX a;
+	double t;
+
+	a = *(C += n);
+	while (n-- > 0) {
+		a.r = (--C)->r + z.r * (t = a.r) - z.i * a.i;
+		a.i = C->i + z.r * a.i + z.i * t;
+	}
+	a.r = z.r * (t = a.r) - z.i * a.i;
+	a.i = z.r * a.i + z.i * t;
+	return a;
+}
+/* evaluate complex polynomial and derivative */
+	COMPLEX
+pj_zpolyd1(COMPLEX z, const COMPLEX *C, int n, COMPLEX *der) {
+	COMPLEX a, b;
+	double t;
+	int first = 1;
+
+	a = *(C += n);
+	b = a;
+	while (n-- > 0) {
+		if (first) {
+			first = 0;
+		} else {
+			b.r = a.r + z.r * (t = b.r) - z.i * b.i;
+			b.i = a.i + z.r * b.i + z.i * t;
+		}
+		a.r = (--C)->r + z.r * (t = a.r) - z.i * a.i;
+		a.i = C->i + z.r * a.i + z.i * t;
+	}
+	b.r = a.r + z.r * (t = b.r) - z.i * b.i;
+	b.i = a.i + z.r * b.i + z.i * t;
+	a.r = z.r * (t = a.r) - z.i * a.i;
+	a.i = z.r * a.i + z.i * t;
+	*der = b;
+	return a;
+}