Remove +scale parameter in favour of good old +k_0

docs/source/operations/projections/lcc.rst

@@ -12,7 +12,7 @@ seven projections introduced by Johann Heinrich Lambert in 1772.
 It has several different forms: with one and two standard parallels
 (referred to as 1SP and 2SP in EPSG guidance notes). Additionally we
 provide "2SP Michigan" form which is very similar to normal 2SP, but
-with a scaling factor on the ellipsoid (given as `scale` parameter).
+with a scaling factor on the ellipsoid (given as `k_0` parameter).
 It is implemented as per EPSG Guidance Note 7-2 (version 54, August
 2018, page 25). It is used in a few systems in the EPSG database which
 justifies adding this otherwise non-standard projection.
@@ -23,7 +23,7 @@ justifies adding this otherwise non-standard projection.
 | **Available forms** | Forward and inverse, spherical and elliptical projection.|
 |                     | One or two standard parallels (1SP and 2SP).             |
 |                     | "LCC 2SP Michigan" form can be used by setting           |
-|                     | `+scale` parameter to specify elliposid scale.           |
+|                     | `+k_0` parameter to specify elliposid scale.             |
 +---------------------+----------------------------------------------------------+
 | **Defined area**    | Best for regions predominantly east–west in extent and   |
 |                     | located in the middle north or south latitudes.          |
@@ -65,9 +65,7 @@ Parameters
 
 .. include:: ../options/y_0.rst
 
-.. include:: ../options/k_0.rst
-
-.. option:: +scale=<value>
+.. option:: +k_0=<value>
 
     Ellipsoid Scale factor. Determines a scale factor used in LCC 2SP
     Michigan variation of the projection.

src/PJ_lcc.c

@@ -5,7 +5,7 @@
 #include "proj_math.h"
 
 PROJ_HEAD(lcc, "Lambert Conformal Conic")
-    "\n\tConic, Sph&Ell\n\tlat_1= and lat_2= or lat_0, scale=";
+    "\n\tConic, Sph&Ell\n\tlat_1= and lat_2= or lat_0, k_0=";
 
 #define EPS10 1.e-10
 
@@ -15,7 +15,6 @@ struct pj_opaque {
     double n;
     double rho0;
     double c;
-    double scale;
 };
 
 
@@ -32,7 +31,7 @@ static XY e_forward (LP lp, PJ *P) {          /* Ellipsoidal, forward */
         rho = 0.;
     } else {
         rho = Q->c * (P->es != 0. ?
-                      Q->scale * pow(pj_tsfn(lp.phi, sin(lp.phi), P->e), Q->n) :
+                      pow(pj_tsfn(lp.phi, sin(lp.phi), P->e), Q->n) :
                       pow(tan(M_FORTPI + .5 * lp.phi), -Q->n));
     }
     lp.lam *= Q->n;
@@ -59,7 +58,7 @@ static LP e_inverse (XY xy, PJ *P) {          /* Ellipsoidal, inverse */
             xy.y = -xy.y;
         }
         if (P->es != 0.) {
-            lp.phi = pj_phi2(P->ctx, pow(rho / (Q->scale * Q->c), 1./Q->n), P->e);
+            lp.phi = pj_phi2(P->ctx, pow(rho / Q->c, 1./Q->n), P->e);
             if (lp.phi == HUGE_VAL) {
                 proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
                 return lp;
@@ -85,10 +84,6 @@ PJ *PROJECTION(lcc) {
         return pj_default_destructor(P, ENOMEM);
     P->opaque = Q;
 
-    Q->scale = 1.;
-    if (pj_param(P->ctx, P->params, "tscale").i)
-      Q->scale = pj_param(P->ctx, P->params, "dscale").f;
-
     Q->phi1 = pj_param(P->ctx, P->params, "rlat_1").f;
     if (pj_param(P->ctx, P->params, "tlat_2").i)
         Q->phi2 = pj_param(P->ctx, P->params, "rlat_2").f;
@@ -115,7 +110,7 @@ PJ *PROJECTION(lcc) {
         }
         Q->c = (Q->rho0 = m1 * pow(ml1, -Q->n) / Q->n);
         Q->rho0 *= (fabs(fabs(P->phi0) - M_HALFPI) < EPS10) ? 0. :
-            Q->scale * pow(pj_tsfn(P->phi0, sin(P->phi0), P->e), Q->n);
+            pow(pj_tsfn(P->phi0, sin(P->phi0), P->e), Q->n);
     } else {
         if (secant)
             Q->n = log(cosphi / cos(Q->phi2)) /

test/gie/builtins.gie

@@ -2535,9 +2535,9 @@ accept  -200 -100
 expect  -0.001796358 -0.000904233
 
 -------------------------------------------------------------------------------
-Tests with +scale (Lambert Conformal Conic 2SP Michigan).
+Tests with +k_0 (Lambert Conformal Conic 2SP Michigan).
 -------------------------------------------------------------------------------
-operation +proj=lcc +ellps=GRS80 +lat_1=0.5 +lat_2=2 +scale=1.0000382
+operation +proj=lcc +ellps=GRS80 +lat_1=0.5 +lat_2=2 +k_0=1.0000382
 -------------------------------------------------------------------------------
 tolerance 0.1 mm
 accept  2 1
@@ -2564,7 +2564,7 @@ expect  -0.001796290 -0.000904199
 Test various corner cases, spherical projection and one standard
 parallel to improve test coverage.
 -------------------------------------------------------------------------------
-operation +proj=lcc   +ellps=GRS80  +lat_1=0.5 +lat_2=2
+operation +proj=lcc +ellps=GRS80 +lat_1=0.5 +lat_2=2
 -------------------------------------------------------------------------------
 tolerance 0.1 mm
 

test/gie/more_builtins.gie

@@ -249,7 +249,7 @@ Tests for LCC 2SP Michigan (from PJ_lcc.c)
 This test is taken from EPSG guidance note 7-2 (version 54, August 2018,
 page 25)
 -------------------------------------------------------------------------------
-operation +proj=lcc +ellps=clrk66 +lat_1=44d11'N +lat_2=45d42'N +x_0=609601.2192 +lon_0=84d20'W +lat_0=43d19'N +scale=1.0000382 +units=us-ft
+operation +proj=lcc +ellps=clrk66 +lat_1=44d11'N +lat_2=45d42'N +x_0=609601.2192 +lon_0=84d20'W +lat_0=43d19'N +k_0=1.0000382 +units=us-ft
 -------------------------------------------------------------------------------
 tolerance 5 mm
 accept 83d10'W 43d45'N