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authorEven Rouault <even.rouault@spatialys.com>2018-12-18 20:24:11 +0100
committerEven Rouault <even.rouault@spatialys.com>2018-12-26 10:08:53 +0100
commit610957f7035242f15743c399ffd429b92bc36206 (patch)
tree73f0d51147e2f4860c4bfc875f7a4bf9359386d4 /src/pj_zpoly1.cpp
parent355d681ed88019e97742344bd642c2fd97e700a1 (diff)
downloadPROJ-610957f7035242f15743c399ffd429b92bc36206.tar.gz
PROJ-610957f7035242f15743c399ffd429b92bc36206.zip
cpp conversion: minimal steps to fix compilation errors, not warnings
Diffstat (limited to 'src/pj_zpoly1.cpp')
-rw-r--r--src/pj_zpoly1.cpp46
1 files changed, 46 insertions, 0 deletions
diff --git a/src/pj_zpoly1.cpp b/src/pj_zpoly1.cpp
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+/* 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;
+}