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| author | Andrew Bell <andrew.bell.ia@gmail.com> | 2019-05-15 10:47:03 -0400 |
|---|---|---|
| committer | Andrew Bell <andrew.bell.ia@gmail.com> | 2019-05-15 10:47:03 -0400 |
| commit | 8f268409d37cea329d263e177b83e42f8384d3c7 (patch) | |
| tree | c4d0f3dd19456600f718a6e0c8573577f433549b /src/projections/robin.cpp | |
| parent | 886ced02f0aaab5d66d16459435f7447cf976650 (diff) | |
| parent | d67203a6f76a74f5ac029ff052dbcc72e3b59624 (diff) | |
| download | PROJ-8f268409d37cea329d263e177b83e42f8384d3c7.tar.gz PROJ-8f268409d37cea329d263e177b83e42f8384d3c7.zip | |
Merge remote-tracking branch 'origin/master'
Diffstat (limited to 'src/projections/robin.cpp')
| -rw-r--r-- | src/projections/robin.cpp | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/src/projections/robin.cpp b/src/projections/robin.cpp index 8f142aad..c08ac0e2 100644 --- a/src/projections/robin.cpp +++ b/src/projections/robin.cpp @@ -1,13 +1,12 @@ #define PJ_LIB__ -#include "proj_math.h" -#include "proj_internal.h" #include "proj.h" #include "proj_internal.h" +#include "proj_math.h" PROJ_HEAD(robin, "Robinson") "\n\tPCyl, Sph"; #define V(C,z) (C.c0 + z * (C.c1 + z * (C.c2 + z * C.c3))) -#define DV(C,z) (C.c1 + z * (C.c2 + C.c2 + z * 3. * C.c3)) +#define DV(C,z) (C.c1 + 2 * z * C.c2 + z * z * 3. * C.c3) /* note: following terms based upon 5 deg. intervals in degrees. @@ -74,11 +73,11 @@ static const struct COEFS Y[] = { #define RC1 0.08726646259971647884 #define NODES 18 #define ONEEPS 1.000001 -#define EPS 1e-8 +#define EPS 1e-10 /* Not sure at all of the appropriate number for MAX_ITER... */ #define MAX_ITER 100 -static PJ_XY s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ +static PJ_XY robin_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ PJ_XY xy = {0.0,0.0}; long i; double dphi; @@ -90,7 +89,7 @@ static PJ_XY s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); return xy; } - if (i >= NODES) i = NODES - 1; + if (i >= NODES) i = NODES; dphi = RAD_TO_DEG * (dphi - RC1 * i); xy.x = V(X[i], dphi) * FXC * lp.lam; xy.y = V(Y[i], dphi) * FYC; @@ -100,7 +99,7 @@ static PJ_XY s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ } -static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ +static PJ_LP robin_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ PJ_LP lp = {0.0,0.0}; long i; double t, t1; @@ -133,10 +132,8 @@ static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ T = Y[i]; /* first guess, linear interp */ t = 5. * (lp.phi - T.c0)/(Y[i+1].c0 - T.c0); - /* make into root */ - T.c0 = (float)(T.c0 - lp.phi); for (iters = MAX_ITER; iters ; --iters) { /* Newton-Raphson */ - t -= t1 = V(T,t) / DV(T,t); + t -= t1 = (V(T,t) - lp.phi) / DV(T,t); if (fabs(t1) < EPS) break; } @@ -152,8 +149,8 @@ static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ PJ *PROJECTION(robin) { P->es = 0.; - P->inv = s_inverse; - P->fwd = s_forward; + P->inv = robin_s_inverse; + P->fwd = robin_s_forward; return P; } |