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C: Added Astronomy_Rotation_EQD_ECL, ECL_EQD, HOR_ECL, ECL_HOR.
These are the final 4 rotation functions to complete every possible coordinate transform. Finished unit tests of verifying that all triangular cycles of transitive rotation are consistent.
This commit is contained in:
Don Cross
@@ -1775,7 +1775,7 @@ static int CheckUnitVector(int lnum, const char *name, astro_rotation_t r, int i
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sum += x*x;
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}
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x = fabs(sum - 1.0);
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if (x > 5e-16)
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if (x > 1.0e-15)
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{
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fprintf(stderr, "ERROR(%s line %d): unit error = %lg for i0=%d, j0=%d, di=%d, dj=%d\n", name, lnum, x, i0, j0, di, dj);
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return 1;
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@@ -2349,6 +2349,24 @@ fail:
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#define CHECK_INVERSE(a,b) CHECK(CheckInverse(#a, #b, a, b))
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static int CheckCycle(
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const char *cyclename,
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astro_rotation_t arot, astro_rotation_t brot, astro_rotation_t crot)
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{
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int error;
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astro_rotation_t xrot;
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xrot = Astronomy_CombineRotation(arot, brot);
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CHECK_ROTMAT(xrot);
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xrot = Astronomy_InverseRotation(xrot);
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CHECK(CompareMatrices(cyclename, crot, xrot, 2.0e-15));
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error = 0;
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fail:
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return error;
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}
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#define CHECK_CYCLE(a,b,c) CHECK(CheckCycle(("CheckCycle: " #a ", " #b ", " #c), a, b, c))
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static int Test_RotRoundTrip(void)
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{
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int error;
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@@ -2358,18 +2376,15 @@ static int Test_RotRoundTrip(void)
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astro_rotation_t eqj_hor, hor_eqj;
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astro_rotation_t eqj_eqd, eqd_eqj;
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astro_rotation_t hor_eqd, eqd_hor;
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//astro_rotation_t eqd_ecl, ecl_eqd;
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//astro_rotation_t hor_ecl, ecl_hor;
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astro_rotation_t eqd_ecl, ecl_eqd;
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astro_rotation_t hor_ecl, ecl_hor;
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time = Astronomy_MakeTime(2067, 5, 30, 14, 45, 0.0);
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observer = Astronomy_MakeObserver(+28.0, -82.0, 0.0);
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/*
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In each round trip, we calculate a forward rotation and a backward rotation.
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In each round trip, calculate a forward rotation and a backward rotation.
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Verify the two are inverse matrices.
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Then verify that combining different sequences of rotations result
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in the expected combination.
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For example, (EQJ ==> HOR ==> ECL) must be the same matrix as (EQJ ==> ECL).
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*/
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/* Round trip #1: EQJ <==> EQD. */
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@@ -2393,14 +2408,28 @@ static int Test_RotRoundTrip(void)
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CHECK_INVERSE(eqd_hor, hor_eqd);
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/* Round trip #5: EQD <==> ECL. */
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//eqd_ecl = Astronomy_Rotation_EQD_ECL(time, observer);
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//ecl_eqd = Astronomy_Rotation_ECL_EQD(time, observer);
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//CHECK_INVERSE(eqd_ecl, ecl_eqd);
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eqd_ecl = Astronomy_Rotation_EQD_ECL(time);
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ecl_eqd = Astronomy_Rotation_ECL_EQD(time);
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CHECK_INVERSE(eqd_ecl, ecl_eqd);
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/* Round trip #6: HOR <==> ECL. */
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//hor_ecl = Astronomy_Rotation_HOR_ECL(time, observer);
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//ecl_hor = Astronomy_Rotation_ECL_HOR(time, observer);
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//CHECK_INVERSE(hor_ecl, ecl_hor);
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hor_ecl = Astronomy_Rotation_HOR_ECL(time, observer);
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ecl_hor = Astronomy_Rotation_ECL_HOR(time, observer);
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CHECK_INVERSE(hor_ecl, ecl_hor);
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/*
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Verify that combining different sequences of rotations result
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in the expected combination.
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For example, (EQJ ==> HOR ==> ECL) must be the same matrix as (EQJ ==> ECL).
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Each of these is a "triangle" of relationships between 3 orientations.
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There are 4 possible ways to pick 3 orientations from the 4 to form a triangle.
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Because we have just proved that each transformation is reversible,
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we only need to verify the triangle in one cyclic direction.
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*/
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CHECK_CYCLE(eqj_ecl, ecl_eqd, eqd_eqj); /* excluded corner = HOR */
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CHECK_CYCLE(eqj_hor, hor_ecl, ecl_eqj); /* excluded corner = EQD */
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CHECK_CYCLE(eqj_hor, hor_eqd, eqd_eqj); /* excluded corner = ECL */
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CHECK_CYCLE(ecl_eqd, eqd_hor, hor_ecl); /* excluded corner = EQJ */
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printf("Test_RotRoundTrip: PASS\n");
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error = 0;
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@@ -4617,6 +4617,110 @@ astro_rotation_t Astronomy_Rotation_EQJ_HOR(astro_time_t time, astro_observer_t
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}
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/**
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* @brief
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* Calculates a rotation matrix from equatorial of-date (EQD) to ecliptic J2000 (ECL).
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*
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* This is one of the family of functions that returns a rotation matrix
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* for converting from one orientation to another.
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* Source: EQD = equatorial system, using equator of date.
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* Target: ECL = ecliptic system, using equator at J2000 epoch.
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*
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* @param time
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* The date and time of the source equator.
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*
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* @return
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* A rotation matrix that converts EQD to ECL.
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*/
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astro_rotation_t Astronomy_Rotation_EQD_ECL(astro_time_t time)
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{
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astro_rotation_t eqd_eqj;
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astro_rotation_t eqj_ecl;
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eqd_eqj = Astronomy_Rotation_EQD_EQJ(time);
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eqj_ecl = Astronomy_Rotation_EQJ_ECL();
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return Astronomy_CombineRotation(eqd_eqj, eqj_ecl);
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}
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/**
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* @brief
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* Calculates a rotation matrix from ecliptic J2000 (ECL) to equatorial of-date (EQD).
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*
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* This is one of the family of functions that returns a rotation matrix
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* for converting from one orientation to another.
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* Source: ECL = ecliptic system, using equator at J2000 epoch.
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* Target: EQD = equatorial system, using equator of date.
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*
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* @param time
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* The date and time of the desired equator.
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*
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* @return
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* A rotation matrix that converts ECL to EQD.
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*/
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astro_rotation_t Astronomy_Rotation_ECL_EQD(astro_time_t time)
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{
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astro_rotation_t rot = Astronomy_Rotation_EQD_ECL(time);
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return Astronomy_InverseRotation(rot);
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}
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/**
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* @brief
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* Calculates a rotation matrix from ecliptic J2000 (ECL) to horizontal (HOR).
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*
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* This is one of the family of functions that returns a rotation matrix
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* for converting from one orientation to another.
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* Source: ECL = ecliptic system, using equator at J2000 epoch.
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* Target: HOR = horizontal system.
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*
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* Use #Astronomy_HorizonFromVector to convert the return value
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* to a traditional altitude/azimuth pair.
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*
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* @param time
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* The date and time of the desired horizontal orientation.
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*
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* @param observer
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* A location near the Earth's mean sea level that defines the observer's horizon.
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*
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* @return
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* A rotation matrix that converts ECL to HOR at `time` and for `observer`.
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* The components of the horizontal vector are:
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* x = north, y = west, z = zenith (straight up from the observer).
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* These components are chosen so that the "right-hand rule" works for the vector
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* and so that north represents the direction where azimuth = 0.
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*/
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astro_rotation_t Astronomy_Rotation_ECL_HOR(astro_time_t time, astro_observer_t observer)
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{
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astro_rotation_t ecl_eqd = Astronomy_Rotation_ECL_EQD(time);
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astro_rotation_t eqd_hor = Astronomy_Rotation_EQD_HOR(time, observer);
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return Astronomy_CombineRotation(ecl_eqd, eqd_hor);
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}
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/**
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* @brief
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* Calculates a rotation matrix from horizontal (HOR) to ecliptic J2000 (ECL).
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*
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* This is one of the family of functions that returns a rotation matrix
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* for converting from one orientation to another.
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* Source: HOR = horizontal system.
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* Target: ECL = ecliptic system, using equator at J2000 epoch.
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*
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* @param time
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* The date and time of the horizontal observation.
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*
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* @param observer
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* The location of the horizontal observer.
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*
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* @return
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* A rotation matrix that converts HOR to ECL.
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*/
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astro_rotation_t Astronomy_Rotation_HOR_ECL(astro_time_t time, astro_observer_t observer)
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{
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astro_rotation_t rot = Astronomy_Rotation_ECL_HOR(time, observer);
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return Astronomy_InverseRotation(rot);
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}
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#ifdef __cplusplus
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}
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#endif
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@@ -760,6 +760,30 @@ This function transforms a vector in one orientation to a vector in another orie
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---
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<a name="Astronomy_Rotation_ECL_EQD"></a>
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### Astronomy_Rotation_ECL_EQD(time) ⇒ [`astro_rotation_t`](#astro_rotation_t)
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**Calculates a rotation matrix from ecliptic J2000 (ECL) to equatorial of-date (EQD).**
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This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: ECL = ecliptic system, using equator at J2000 epoch. Target: EQD = equatorial system, using equator of date.
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**Returns:** A rotation matrix that converts ECL to EQD.
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| Type | Parameter | Description |
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| --- | --- | --- |
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| [`astro_time_t`](#astro_time_t) | `time` | The date and time of the desired equator. |
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---
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<a name="Astronomy_Rotation_ECL_EQJ"></a>
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@@ -777,6 +801,57 @@ This is one of the family of functions that returns a rotation matrix for conver
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---
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<a name="Astronomy_Rotation_ECL_HOR"></a>
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### Astronomy_Rotation_ECL_HOR(time, observer) ⇒ [`astro_rotation_t`](#astro_rotation_t)
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**Calculates a rotation matrix from ecliptic J2000 (ECL) to horizontal (HOR).**
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This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: ECL = ecliptic system, using equator at J2000 epoch. Target: HOR = horizontal system.
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Use [`Astronomy_HorizonFromVector`](#Astronomy_HorizonFromVector) to convert the return value to a traditional altitude/azimuth pair.
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**Returns:** A rotation matrix that converts ECL to HOR at `time` and for `observer`. The components of the horizontal vector are: x = north, y = west, z = zenith (straight up from the observer). These components are chosen so that the "right-hand rule" works for the vector and so that north represents the direction where azimuth = 0.
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| Type | Parameter | Description |
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| --- | --- | --- |
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| [`astro_time_t`](#astro_time_t) | `time` | The date and time of the desired horizontal orientation. |
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| [`astro_observer_t`](#astro_observer_t) | `observer` | A location near the Earth's mean sea level that defines the observer's horizon. |
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---
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<a name="Astronomy_Rotation_EQD_ECL"></a>
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### Astronomy_Rotation_EQD_ECL(time) ⇒ [`astro_rotation_t`](#astro_rotation_t)
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**Calculates a rotation matrix from equatorial of-date (EQD) to ecliptic J2000 (ECL).**
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This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: EQD = equatorial system, using equator of date. Target: ECL = ecliptic system, using equator at J2000 epoch.
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**Returns:** A rotation matrix that converts EQD to ECL.
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| Type | Parameter | Description |
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| --- | --- | --- |
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| [`astro_time_t`](#astro_time_t) | `time` | The date and time of the source equator. |
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---
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<a name="Astronomy_Rotation_EQD_EQJ"></a>
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@@ -896,6 +971,31 @@ Use [`Astronomy_HorizonFromVector`](#Astronomy_HorizonFromVector) to convert the
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---
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<a name="Astronomy_Rotation_HOR_ECL"></a>
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### Astronomy_Rotation_HOR_ECL(time, observer) ⇒ [`astro_rotation_t`](#astro_rotation_t)
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**Calculates a rotation matrix from horizontal (HOR) to ecliptic J2000 (ECL).**
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This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: HOR = horizontal system. Target: ECL = ecliptic system, using equator at J2000 epoch.
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**Returns:** A rotation matrix that converts HOR to ECL.
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| Type | Parameter | Description |
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| --- | --- | --- |
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| [`astro_time_t`](#astro_time_t) | `time` | The date and time of the horizontal observation. |
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| [`astro_observer_t`](#astro_observer_t) | `observer` | The location of the horizontal observer. |
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---
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<a name="Astronomy_Rotation_HOR_EQD"></a>
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@@ -5856,6 +5856,110 @@ astro_rotation_t Astronomy_Rotation_EQJ_HOR(astro_time_t time, astro_observer_t
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}
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/**
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* @brief
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* Calculates a rotation matrix from equatorial of-date (EQD) to ecliptic J2000 (ECL).
|
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*
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* This is one of the family of functions that returns a rotation matrix
|
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* for converting from one orientation to another.
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* Source: EQD = equatorial system, using equator of date.
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* Target: ECL = ecliptic system, using equator at J2000 epoch.
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*
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* @param time
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* The date and time of the source equator.
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*
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* @return
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* A rotation matrix that converts EQD to ECL.
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*/
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astro_rotation_t Astronomy_Rotation_EQD_ECL(astro_time_t time)
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{
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astro_rotation_t eqd_eqj;
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astro_rotation_t eqj_ecl;
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eqd_eqj = Astronomy_Rotation_EQD_EQJ(time);
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eqj_ecl = Astronomy_Rotation_EQJ_ECL();
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return Astronomy_CombineRotation(eqd_eqj, eqj_ecl);
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}
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/**
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* @brief
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* Calculates a rotation matrix from ecliptic J2000 (ECL) to equatorial of-date (EQD).
|
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*
|
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* This is one of the family of functions that returns a rotation matrix
|
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* for converting from one orientation to another.
|
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* Source: ECL = ecliptic system, using equator at J2000 epoch.
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* Target: EQD = equatorial system, using equator of date.
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*
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* @param time
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* The date and time of the desired equator.
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*
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* @return
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* A rotation matrix that converts ECL to EQD.
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*/
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astro_rotation_t Astronomy_Rotation_ECL_EQD(astro_time_t time)
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{
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astro_rotation_t rot = Astronomy_Rotation_EQD_ECL(time);
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return Astronomy_InverseRotation(rot);
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}
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/**
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* @brief
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* Calculates a rotation matrix from ecliptic J2000 (ECL) to horizontal (HOR).
|
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*
|
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* This is one of the family of functions that returns a rotation matrix
|
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* for converting from one orientation to another.
|
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* Source: ECL = ecliptic system, using equator at J2000 epoch.
|
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* Target: HOR = horizontal system.
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*
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* Use #Astronomy_HorizonFromVector to convert the return value
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* to a traditional altitude/azimuth pair.
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*
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* @param time
|
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* The date and time of the desired horizontal orientation.
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*
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* @param observer
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* A location near the Earth's mean sea level that defines the observer's horizon.
|
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*
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* @return
|
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* A rotation matrix that converts ECL to HOR at `time` and for `observer`.
|
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* The components of the horizontal vector are:
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* x = north, y = west, z = zenith (straight up from the observer).
|
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* These components are chosen so that the "right-hand rule" works for the vector
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* and so that north represents the direction where azimuth = 0.
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*/
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astro_rotation_t Astronomy_Rotation_ECL_HOR(astro_time_t time, astro_observer_t observer)
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{
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astro_rotation_t ecl_eqd = Astronomy_Rotation_ECL_EQD(time);
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astro_rotation_t eqd_hor = Astronomy_Rotation_EQD_HOR(time, observer);
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return Astronomy_CombineRotation(ecl_eqd, eqd_hor);
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}
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/**
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* @brief
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* Calculates a rotation matrix from horizontal (HOR) to ecliptic J2000 (ECL).
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||||
*
|
||||
* This is one of the family of functions that returns a rotation matrix
|
||||
* for converting from one orientation to another.
|
||||
* Source: HOR = horizontal system.
|
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* Target: ECL = ecliptic system, using equator at J2000 epoch.
|
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*
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* @param time
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* The date and time of the horizontal observation.
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*
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* @param observer
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* The location of the horizontal observer.
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*
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* @return
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* A rotation matrix that converts HOR to ECL.
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*/
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astro_rotation_t Astronomy_Rotation_HOR_ECL(astro_time_t time, astro_observer_t observer)
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{
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astro_rotation_t rot = Astronomy_Rotation_ECL_HOR(time, observer);
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return Astronomy_InverseRotation(rot);
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}
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#ifdef __cplusplus
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}
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#endif
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@@ -620,17 +620,17 @@ astro_spherical_t Astronomy_HorizonFromVector(astro_vector_t vector, astro_refra
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astro_vector_t Astronomy_RotateVector(astro_rotation_t rotation, astro_vector_t vector);
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astro_rotation_t Astronomy_Rotation_EQD_EQJ(astro_time_t time);
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//astro_rotation_t Astronomy_Rotation_EQD_ECL(astro_time_t time);
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astro_rotation_t Astronomy_Rotation_EQD_ECL(astro_time_t time);
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astro_rotation_t Astronomy_Rotation_EQD_HOR(astro_time_t time, astro_observer_t observer);
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astro_rotation_t Astronomy_Rotation_EQJ_EQD(astro_time_t time);
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astro_rotation_t Astronomy_Rotation_EQJ_ECL(void);
|
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astro_rotation_t Astronomy_Rotation_EQJ_HOR(astro_time_t time, astro_observer_t observer);
|
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//astro_rotation_t Astronomy_Rotation_ECL_EQD(astro_time_t time);
|
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astro_rotation_t Astronomy_Rotation_ECL_EQD(astro_time_t time);
|
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astro_rotation_t Astronomy_Rotation_ECL_EQJ(void);
|
||||
//astro_rotation_t Astronomy_Rotation_ECL_HOR(astro_time_t time, astro_observer_t observer);
|
||||
astro_rotation_t Astronomy_Rotation_ECL_HOR(astro_time_t time, astro_observer_t observer);
|
||||
astro_rotation_t Astronomy_Rotation_HOR_EQD(astro_time_t time, astro_observer_t observer);
|
||||
astro_rotation_t Astronomy_Rotation_HOR_EQJ(astro_time_t time, astro_observer_t observer);
|
||||
//astro_rotation_t Astronomy_Rotation_HOR_ECL(astro_time_t time, astro_observer_t observer);
|
||||
astro_rotation_t Astronomy_Rotation_HOR_ECL(astro_time_t time, astro_observer_t observer);
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user