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| author | Kristian Evers <kristianevers@gmail.com> | 2018-12-26 10:53:01 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-12-26 10:53:01 +0100 |
| commit | 81ec8c0b58d66333fccd3703dab62a11132a0331 (patch) | |
| tree | 41b4675d169f849516649700ab4f50d4cffa4c02 /src/zpoly1.cpp | |
| parent | 355d681ed88019e97742344bd642c2fd97e700a1 (diff) | |
| parent | 80dad6ef2bed4a83008db06986dc168918d48476 (diff) | |
| download | PROJ-81ec8c0b58d66333fccd3703dab62a11132a0331.tar.gz PROJ-81ec8c0b58d66333fccd3703dab62a11132a0331.zip | |
Merge pull request #1203 from rouault/cpp_conversion
Conversion of most C files to C++
Diffstat (limited to 'src/zpoly1.cpp')
| -rw-r--r-- | src/zpoly1.cpp | 46 |
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; +} |
