private static IEnumerable<ProjectionParameter> VerifyParameters(IEnumerable<ProjectionParameter> parameters)
{
var p = new ProjectionParameterSet(parameters);
var semi_major = p.GetParameterValue("semi_major");
p.SetParameterValue("semi_minor", semi_major);
p.SetParameterValue("scale_factor", 1);
return p.ToProjectionParameter();
}
/// <summary>
/// Creates an instance of this class
/// </summary>
/// <param name="parameters">An enumeration of projection parameters</param>
protected MapProjection(IEnumerable<ProjectionParameter> parameters)
{
_Parameters = new ProjectionParameterSet(parameters);
_semiMajor = _Parameters.GetParameterValue("semi_major");
_semiMinor = _Parameters.GetParameterValue("semi_minor");
//_es = 1.0 - (_semiMinor * _semiMinor) / (_semiMajor * _semiMajor);
_es = EccentricySquared(_semiMajor, _semiMinor);
_e = Math.Sqrt(_es);
scale_factor = _Parameters.GetOptionalParameterValue("scale_factor", 1);
central_meridian = Degrees2Radians(_Parameters.GetParameterValue("central_meridian", "longitude_of_center"));
lat_origin = Degrees2Radians(_Parameters.GetParameterValue("latitude_of_origin", "latitude_of_center"));
_metersPerUnit = _Parameters.GetParameterValue("unit");
false_easting = _Parameters.GetOptionalParameterValue("false_easting", 0)*_metersPerUnit;
false_northing = _Parameters.GetOptionalParameterValue("false_northing", 0)*_metersPerUnit;
// TODO: Should really convert to the correct linear units??
// Compute constants for the mlfn
double t;
en0 = C00 - _es*(C02 + _es*
(C04 + _es*(C06 + _es*C08)));
en1 = _es*(C22 - _es*
(C04 + _es*(C06 + _es*C08)));
en2 = (t = _es*_es)*
(C44 - _es*(C46 + _es*C48));
en3 = (t *= _es)*(C66 - _es*C68);
en4 = t*_es*C88;
}
