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Attempt to further isolate domain error problem.

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This commit is contained in:
curt
2001-01-24 04:11:36 +00:00
parent 22b41d892a
commit fad34bdbc3
1 changed files with 47 additions and 13 deletions
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simgear/math/sg_geodesy.cxx
+47 -13
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@@ -12,9 +12,11 @@
#ifdef FG_HAVE_STD_INCLUDES #ifdef FG_HAVE_STD_INCLUDES
# include <cmath> # include <cmath>
# include <cerrno> # include <cerrno>
# include <cstdio>
#else #else
# include <math.h> # include <math.h>
# include <errno.h> # include <errno.h>
# include <stdio.h>
#endif #endif
#include <simgear/constants.h> #include <simgear/constants.h>
@@ -33,6 +35,9 @@ FG_USING_STD(cout);
#define ONE_SECOND 4.848136811E-6 #define ONE_SECOND 4.848136811E-6
#define DOMAIN_ERR_DEBUG 1
// sgGeocToGeod(lat_geoc, radius, *lat_geod, *alt, *sea_level_r) // sgGeocToGeod(lat_geoc, radius, *lat_geod, *alt, *sea_level_r)
// INPUTS: // INPUTS:
// lat_geoc Geocentric latitude, radians, + = North // lat_geoc Geocentric latitude, radians, + = North
@@ -48,6 +53,10 @@ FG_USING_STD(cout);
void sgGeocToGeod( double lat_geoc, double radius, double void sgGeocToGeod( double lat_geoc, double radius, double
*lat_geod, double *alt, double *sea_level_r ) *lat_geod, double *alt, double *sea_level_r )
{ {
#ifdef DOMAIN_ERR_DEBUG
errno = 0; // start with error zero'd
#endif
double t_lat, x_alpha, mu_alpha, delt_mu, r_alpha, l_point, rho_alpha; double t_lat, x_alpha, mu_alpha, delt_mu, r_alpha, l_point, rho_alpha;
double sin_mu_a, denom,delt_lambda, lambda_sl, sin_lambda_sl; double sin_mu_a, denom,delt_lambda, lambda_sl, sin_lambda_sl;
@@ -62,10 +71,23 @@ void sgGeocToGeod( double lat_geoc, double radius, double
t_lat = tan(lat_geoc); t_lat = tan(lat_geoc);
// cout << " tan(t_lat) = " << t_lat << endl; // cout << " tan(t_lat) = " << t_lat << endl;
x_alpha = E*EQUATORIAL_RADIUS_M/sqrt(t_lat*t_lat + E*E); x_alpha = E*EQUATORIAL_RADIUS_M/sqrt(t_lat*t_lat + E*E);
#ifdef DOMAIN_ERR_DEBUG
if ( errno ) {
perror("fgGeocToGeod()");
FG_LOG( FG_GENERAL, FG_ALERT, "sqrt(" << t_lat*t_lat + E*E << ")" );
}
#endif
// cout << " x_alpha = " << x_alpha << endl; // cout << " x_alpha = " << x_alpha << endl;
double tmp = RESQ_M - x_alpha * x_alpha; double tmp = sqrt(RESQ_M - x_alpha * x_alpha);
if ( tmp < 0.0 ) { tmp = 0.0; } if ( tmp < 0.0 ) { tmp = 0.0; }
mu_alpha = atan2(sqrt(tmp),E*x_alpha); #ifdef DOMAIN_ERR_DEBUG
if ( errno ) {
perror("fgGeocToGeod()");
FG_LOG( FG_GENERAL, FG_ALERT, "sqrt(" << RESQ_M - x_alpha * x_alpha
<< ")" );
}
#endif
mu_alpha = atan2(tmp,E*x_alpha);
if (lat_geoc < 0) mu_alpha = - mu_alpha; if (lat_geoc < 0) mu_alpha = - mu_alpha;
sin_mu_a = sin(mu_alpha); sin_mu_a = sin(mu_alpha);
delt_lambda = mu_alpha - lat_geoc; delt_lambda = mu_alpha - lat_geoc;
@@ -73,13 +95,14 @@ void sgGeocToGeod( double lat_geoc, double radius, double
l_point = radius - r_alpha; l_point = radius - r_alpha;
*alt = l_point*cos(delt_lambda); *alt = l_point*cos(delt_lambda);
// check for domain error
if ( errno == EDOM ) {
FG_LOG( FG_GENERAL, FG_ALERT, "Domain ERROR in fgGeocToGeod!!!!" );
*alt = 0.0;
}
denom = sqrt(1-EPS*EPS*sin_mu_a*sin_mu_a); denom = sqrt(1-EPS*EPS*sin_mu_a*sin_mu_a);
#ifdef DOMAIN_ERR_DEBUG
if ( errno ) {
perror("fgGeocToGeod()");
FG_LOG( FG_GENERAL, FG_ALERT, "sqrt(" <<
1-EPS*EPS*sin_mu_a*sin_mu_a << ")" );
}
#endif
rho_alpha = EQUATORIAL_RADIUS_M*(1-EPS)/ rho_alpha = EQUATORIAL_RADIUS_M*(1-EPS)/
(denom*denom*denom); (denom*denom*denom);
delt_mu = atan2(l_point*sin(delt_lambda),rho_alpha + *alt); delt_mu = atan2(l_point*sin(delt_lambda),rho_alpha + *alt);
@@ -88,12 +111,15 @@ void sgGeocToGeod( double lat_geoc, double radius, double
sin_lambda_sl = sin( lambda_sl ); sin_lambda_sl = sin( lambda_sl );
*sea_level_r = *sea_level_r =
sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl)); sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl));
#ifdef DOMAIN_ERR_DEBUG
// check for domain error if ( errno ) {
if ( errno == EDOM ) { perror("fgGeocToGeod()");
FG_LOG( FG_GENERAL, FG_ALERT, "Domain ERROR in sgGeocToGeod!!!!" ); FG_LOG( FG_GENERAL, FG_ALERT, "sqrt(" <<
*sea_level_r = 0.0; RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl)
<< ")" );
} }
#endif
} }
} }
@@ -123,6 +149,14 @@ void sgGeodToGeoc( double lat_geod, double alt, double *sl_radius,
cos_mu = cos(lat_geod); cos_mu = cos(lat_geod);
*sl_radius = *sl_radius =
sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl)); sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl));
#ifdef DOMAIN_ERR_DEBUG
if ( errno ) {
perror("fgGeodToGeoc()");
FG_LOG( FG_GENERAL, FG_ALERT, "sqrt(" <<
RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl)
<< ")" );
}
#endif
py = *sl_radius*sin_lambda_sl + alt*sin_mu; py = *sl_radius*sin_lambda_sl + alt*sin_mu;
px = *sl_radius*cos_lambda_sl + alt*cos_mu; px = *sl_radius*cos_lambda_sl + alt*cos_mu;
*lat_geoc = atan2( py, px ); *lat_geoc = atan2( py, px );