diff options
| -rw-r--r-- | src/projections/ocea.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/projections/ocea.cpp b/src/projections/ocea.cpp index 4930e587..4e28f727 100644 --- a/src/projections/ocea.cpp +++ b/src/projections/ocea.cpp @@ -87,7 +87,16 @@ PJ *PROJECTION(ocea) { lam_p = -lam_p; /*Equation 9-2 page 80 (http://pubs.usgs.gov/pp/1395/report.pdf)*/ - phi_p = atan(-cos(lam_p - lam_1) / tan(phi_1)); + double cos_lamp_m_minus_lam_1 = cos(lam_p - lam_1); + double tan_phi_1 = tan(phi_1); + if( tan_phi_1 == 0.0 ) { + // Not sure if we want to support this case, but at least this avoids + // a division by zero, and gives the same result as the below atan() + phi_p = (cos_lamp_m_minus_lam_1 >= 0.0 ) ? -M_HALFPI : M_HALFPI; + } + else { + phi_p = atan(- cos_lamp_m_minus_lam_1 / tan_phi_1); + } } P->lam0 = lam_p + M_HALFPI; Q->cosphi = cos(phi_p); |