mirror of https://github.com/ecmwf/eccodes.git
ECC-1364: Cleanup
This commit is contained in:
Shahram Najm
parent
db48ecd3a9
commit
6dbbf152b7
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@ -85,21 +85,21 @@ static void init_class(grib_iterator_class* c)
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#define EPSILON 1.0e-10
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#ifndef M_PI
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#define M_PI 3.14159265358979323846 /* Whole pie */
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#define M_PI 3.14159265358979323846 // Whole pie
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#endif
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#ifndef M_PI_2
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#define M_PI_2 1.57079632679489661923 /* Half a pie */
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#define M_PI_2 1.57079632679489661923 // Half a pie
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#endif
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#ifndef M_PI_4
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#define M_PI_4 0.78539816339744830962 /* Quarter of a pie */
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#define M_PI_4 0.78539816339744830962 // Quarter of a pie
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#endif
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#define RAD2DEG 57.29577951308232087684 /* 180 over pi */
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#define DEG2RAD 0.01745329251994329576 /* pi over 180 */
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#define RAD2DEG 57.29577951308232087684 // 180 over pi
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#define DEG2RAD 0.01745329251994329576 // pi over 180
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/* Adjust longitude (in radians) to range -180 to 180 */
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// Adjust longitude (in radians) to range -180 to 180
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static double adjust_lon_radians(double lon)
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{
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if (lon > M_PI) lon -= 2 * M_PI;
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@ -107,16 +107,15 @@ static double adjust_lon_radians(double lon)
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return lon;
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}
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/* Function to compute the latitude angle, phi2, for the inverse
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* From the book "Map Projections-A Working Manual-John P. Snyder (1987)"
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* Equation (7-9) involves rapidly converging iteration: Calculate t from (15-11)
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* Then, assuming an initial trial phi equal to (pi/2 - 2*arctan t) in the right side of equation (7-9),
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* calculate phi on the left side. Substitute the calculated phi) into the right side,
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* calculate a new phi, etc., until phi does not change significantly from the preceding trial value of phi
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*/
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// Function to compute the latitude angle, phi2, for the inverse
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// From the book "Map Projections-A Working Manual-John P. Snyder (1987)"
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// Equation (7-9) involves rapidly converging iteration: Calculate t from (15-11)
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// Then, assuming an initial trial phi equal to (pi/2 - 2*arctan t) in the right side of equation (7-9),
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// calculate phi on the left side. Substitute the calculated phi) into the right side,
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// calculate a new phi, etc., until phi does not change significantly from the preceding trial value of phi
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static double compute_phi(
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double eccent, /* Spheroid eccentricity */
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double ts, /* Constant value t */
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double eccent, // Spheroid eccentricity
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double ts, // Constant value t
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int* error)
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{
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double eccnth, phi, con, dphi, sinpi;
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@ -136,19 +135,19 @@ static double compute_phi(
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return 0;
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}
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/* Compute the constant small m which is the radius of
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a parallel of latitude, phi, divided by the semimajor axis */
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// Compute the constant small m which is the radius of
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// a parallel of latitude, phi, divided by the semimajor axis
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static double compute_m(double eccent, double sinphi, double cosphi)
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{
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const double con = eccent * sinphi;
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return ((cosphi / (sqrt(1.0 - con * con))));
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}
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/* Compute the constant small t for use in the forward computations */
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// Compute the constant small t for use in the forward computations
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static double compute_t(
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double eccent, /* Eccentricity of the spheroid */
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double phi, /* Latitude phi */
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double sinphi) /* Sine of the latitude */
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double eccent, // Eccentricity of the spheroid
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double phi, // Latitude phi
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double sinphi) // Sine of the latitude
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{
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double con = eccent * sinphi;
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double com = 0.5 * eccent;
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@ -162,10 +161,12 @@ static double calculate_eccentricity(double minor, double major)
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return sqrt(1.0 - temp * temp);
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}
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static void xy2latlon(double radius, double n, double f, double rho0_bare, double LoVInRadians,
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static void xy2lonlat(double radius, double n, double f, double rho0_bare, double LoVInRadians,
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double x, double y,
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double* latDeg, double* lonDeg)
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double* lonDeg, double* latDeg)
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{
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DEBUG_ASSERT(radius > 0);
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DEBUG_ASSERT(n != 0.0);
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x /= radius;
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y /= radius;
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y = rho0_bare - y;
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@ -176,10 +177,10 @@ static void xy2latlon(double radius, double n, double f, double rho0_bare, doubl
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x = -x;
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y = -y;
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}
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double lp_phi = 2. * atan(pow(f / rho, 1.0/n)) - M_PI_2;
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double lp_lam = atan2(x, y) / n;
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*lonDeg = lp_lam*RAD2DEG + LoVInRadians*RAD2DEG;
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*latDeg = lp_phi*RAD2DEG;
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double latRadians = 2. * atan(pow(f / rho, 1.0/n)) - M_PI_2;
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double lonRadians = atan2(x, y) / n;
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*lonDeg = (lonRadians + LoVInRadians) * RAD2DEG;
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*latDeg = latRadians * RAD2DEG;
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}
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else {
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*lonDeg = 0.0;
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@ -196,7 +197,7 @@ static int init_sphere(const grib_handle* h,
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double LoVInRadians, double Latin1InRadians, double Latin2InRadians,
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double LaDInRadians)
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{
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double n, angle, x0, y0, x, y;
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double n, x, y;
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if (fabs(Latin1InRadians - Latin2InRadians) < 1E-09) {
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n = sin(Latin1InRadians);
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@ -208,25 +209,22 @@ static int init_sphere(const grib_handle* h,
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double f = (cos(Latin1InRadians) * pow(tan(M_PI_4 + Latin1InRadians / 2.0), n)) / n;
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double rho = radius * f * pow(tan(M_PI_4 + latFirstInRadians / 2.0), -n);
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double rho0_bare = f * pow(tan(M_PI_4 + LaDInRadians / 2.0), -n);
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double rho0 = radius * rho0_bare;
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//if (n < 0) /* adjustment for southern hemisphere */
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// rho0 = -rho0;
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double rho0 = radius * rho0_bare; // scaled
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double lonDiff = lonFirstInRadians - LoVInRadians;
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/* Adjust longitude to range -180 to 180 */
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// Adjust longitude to range -180 to 180
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if (lonDiff > M_PI)
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lonDiff -= 2 * M_PI;
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if (lonDiff < -M_PI)
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lonDiff += 2 * M_PI;
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angle = n * lonDiff;
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x0 = rho * sin(angle);
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y0 = rho0 - rho * cos(angle);
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/*Dx = iScansNegatively == 0 ? Dx : -Dx;*/
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/* GRIB-405: Don't change sign of Dy. Latitudes ALWAYS increase from latitudeOfFirstGridPoint */
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/*Dy = jScansPositively == 1 ? Dy : -Dy;*/
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double angle = n * lonDiff;
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double x0 = rho * sin(angle);
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double y0 = rho0 - rho * cos(angle);
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// Dx = iScansNegatively == 0 ? Dx : -Dx;
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// GRIB-405: Don't change sign of Dy. Latitudes ALWAYS increase from latitudeOfFirstGridPoint
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// Dy = jScansPositively == 1 ? Dy : -Dy;
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/* Allocate latitude and longitude arrays */
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// Allocate latitude and longitude arrays
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self->lats = (double*)grib_context_malloc(h->context, nv * sizeof(double));
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if (!self->lats) {
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grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Error allocating %zu bytes", ITER, nv * sizeof(double));
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@ -244,13 +242,13 @@ static int init_sphere(const grib_handle* h,
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for (long i = 0; i < nx; i++) {
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const long index = i + j * nx;
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x = x0 + i * Dx;
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xy2latlon(radius, n, f, rho0_bare, LoVInRadians, x, y, &latDeg, &lonDeg);
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xy2lonlat(radius, n, f, rho0_bare, LoVInRadians, x, y, &lonDeg, &latDeg);
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self->lons[index] = lonDeg;
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self->lats[index] = latDeg;
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}
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}
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#if 0
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/* Populate our arrays */
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for (j = 0; j < ny; j++) {
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y = y0 + j * Dy;
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//if (n < 0) { /* adjustment for southern hemisphere */
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@ -260,8 +258,7 @@ static int init_sphere(const grib_handle* h,
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tmp2 = tmp * tmp;
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for (i = 0; i < nx; i++) {
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int index = i + j * nx;
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x = x0 + i * Dx;
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//printf("j=%d i=%d xy= %.6f %.6f\t",j,i,x,y);
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x = x0 + i * Dx;
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//if (n < 0) { /* adjustment for southern hemisphere */
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// x = -x;
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//}
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@ -279,7 +276,7 @@ static int init_sphere(const grib_handle* h,
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return GRIB_SUCCESS;
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}
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/* Oblate spheroid */
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// Oblate spheroid
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static int init_oblate(const grib_handle* h,
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grib_iterator_lambert_conformal* self,
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size_t nv, long nx, long ny,
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@ -292,20 +289,20 @@ static int init_oblate(const grib_handle* h,
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{
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int i, j, err = 0;
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double x0, y0, x, y, latRad, lonRad, latDeg, lonDeg, sinphi, ts, rh1, theta;
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double false_easting; /* x offset in meters */
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double false_northing; /* y offset in meters */
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double false_easting; // x offset in meters
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double false_northing; // y offset in meters
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double ns; /* ratio of angle between meridian */
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double F; /* flattening of ellipsoid */
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double rh; /* height above ellipsoid */
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double sin_po; /* sin value */
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double cos_po; /* cos value */
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double con; /* temporary variable */
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double ms1; /* small m 1 */
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double ms2; /* small m 2 */
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double ts0; /* small t 0 */
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double ts1; /* small t 1 */
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double ts2; /* small t 2 */
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double ns; // ratio of angle between meridian
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double F; // flattening of ellipsoid
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double rh; // height above ellipsoid
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double sin_po; // sin value
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double cos_po; // cos value
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double con; // temporary variable
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double ms1; // small m 1
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double ms2; // small m 2
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double ts0; // small t 0
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double ts1; // small t 1
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double ts2; // small t 2
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double e = calculate_eccentricity(earthMinorAxisInMetres, earthMajorAxisInMetres);
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@ -330,7 +327,7 @@ static int init_oblate(const grib_handle* h,
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F = ms1 / (ns * pow(ts1, ns));
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rh = earthMajorAxisInMetres * F * pow(ts0, ns);
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/* Forward projection: convert lat,lon to x,y */
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// Forward projection: convert lat,lon to x,y
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con = fabs(fabs(latFirstInRadians) - M_PI_2);
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if (con > EPSILON) {
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sinphi = sin(latFirstInRadians);
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@ -350,7 +347,7 @@ static int init_oblate(const grib_handle* h,
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x0 = -x0;
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y0 = -y0;
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/* Allocate latitude and longitude arrays */
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// Allocate latitude and longitude arrays
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self->lats = (double*)grib_context_malloc(h->context, nv * sizeof(double));
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if (!self->lats) {
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grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Error allocating %zu bytes", ITER, nv * sizeof(double));
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@ -362,7 +359,7 @@ static int init_oblate(const grib_handle* h,
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return GRIB_OUT_OF_MEMORY;
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}
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/* Populate our arrays */
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// Populate our arrays
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false_easting = x0;
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false_northing = y0;
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for (j = 0; j < ny; j++) {
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@ -371,7 +368,7 @@ static int init_oblate(const grib_handle* h,
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const int index = i + j * nx;
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double _x, _y;
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x = i * Dx;
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/* Inverse projection to convert from x,y to lat,lon */
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// Inverse projection to convert from x,y to lat,lon
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_x = x - false_easting;
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_y = rh - y + false_northing;
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rh1 = sqrt(_x * _x + _y * _y);
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@ -401,7 +398,7 @@ static int init_oblate(const grib_handle* h,
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if (i == 0 && j == 0) {
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DEBUG_ASSERT(fabs(latFirstInRadians - latRad) <= EPSILON);
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}
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latDeg = latRad * RAD2DEG; /* Convert to degrees */
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latDeg = latRad * RAD2DEG; // Convert to degrees
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lonDeg = normalise_longitude_in_degrees(lonRad * RAD2DEG);
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self->lons[index] = lonDeg;
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self->lats[index] = latDeg;
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@ -431,7 +428,7 @@ static int init(grib_iterator* iter, grib_handle* h, grib_arguments* args)
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const char* sLatin2InDegrees = grib_arguments_get_name(h, args, self->carg++);
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const char* slatFirstInDegrees = grib_arguments_get_name(h, args, self->carg++);
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const char* slonFirstInDegrees = grib_arguments_get_name(h, args, self->carg++);
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/* Dx and Dy are in Metres */
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// Dx and Dy are in Metres
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const char* sDx = grib_arguments_get_name(h, args, self->carg++);
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const char* sDy = grib_arguments_get_name(h, args, self->carg++);
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const char* siScansNegatively = grib_arguments_get_name(h, args, self->carg++);
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@ -481,16 +478,16 @@ static int init(grib_iterator* iter, grib_handle* h, grib_arguments* args)
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if ((err = grib_get_long_internal(h, salternativeRowScanning, &alternativeRowScanning)) != GRIB_SUCCESS)
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return err;
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/* Standard Parallels cannot be equal and on opposite sides of the equator */
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// Standard Parallels cannot be equal and on opposite sides of the equator
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if (fabs(Latin1InDegrees + Latin2InDegrees) < EPSILON) {
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grib_context_log(h->context, GRIB_LOG_ERROR,
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"%s: Cannot have equal latitudes for standard parallels on opposite sides of equator", ITER);
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return GRIB_WRONG_GRID;
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}
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/*
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* See Wolfram MathWorld: http://mathworld.wolfram.com/LambertConformalConicProjection.html
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*/
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//
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// See Wolfram MathWorld: http://mathworld.wolfram.com/LambertConformalConicProjection.html
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//
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latFirstInRadians = latFirstInDegrees * DEG2RAD;
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lonFirstInRadians = lonFirstInDegrees * DEG2RAD;
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Latin1InRadians = Latin1InDegrees * DEG2RAD;
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@ -516,7 +513,7 @@ static int init(grib_iterator* iter, grib_handle* h, grib_arguments* args)
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iter->e = -1;
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/* Apply the scanning mode flags which may require data array to be transformed */
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// Apply the scanning mode flags which may require data array to be transformed
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err = transform_iterator_data(h->context, iter->data,
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iScansNegatively, jScansPositively, jPointsAreConsecutive, alternativeRowScanning,
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iter->nv, nx, ny);
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