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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/qsfn.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/qsfn.cpp')
| -rw-r--r-- | src/qsfn.cpp | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/qsfn.cpp b/src/qsfn.cpp new file mode 100644 index 00000000..c18a7b95 --- /dev/null +++ b/src/qsfn.cpp @@ -0,0 +1,22 @@ +/* determine small q */ +#include <math.h> +#include "projects.h" + +# define EPSILON 1.0e-7 + +double pj_qsfn(double sinphi, double e, double one_es) { + double con, div1, div2; + + if (e >= EPSILON) { + con = e * sinphi; + div1 = 1.0 - con * con; + div2 = 1.0 + con; + + /* avoid zero division, fail gracefully */ + if (div1 == 0.0 || div2 == 0.0) + return HUGE_VAL; + + return (one_es * (sinphi / div1 - (.5 / e) * log ((1. - con) / div2 ))); + } else + return (sinphi + sinphi); +} |
