From 2c66023e0692b32187e62beaaf3d456ef0c8a602 Mon Sep 17 00:00:00 2001
From: Micah Cochran <micahcochran@users.noreply.github.com>
Date: Sun, 27 Mar 2016 12:32:06 -0500
Subject: Note revisions. Add licensing. Add supplemental information about
 project, algorithm, and algorithm lineage.

---
 src/PJ_patterson.c | 68 ++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 48 insertions(+), 20 deletions(-)

(limited to 'src')

diff --git a/src/PJ_patterson.c b/src/PJ_patterson.c
index 0483bf6e..6fa10c28 100644
--- a/src/PJ_patterson.c
+++ b/src/PJ_patterson.c
@@ -1,17 +1,45 @@
 /*
- * The Patterson projection was designed by Tom Patterson, US National
+ * Copyright (c) 2014 Bojan Savric
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+/*
+ * The Patterson Cylindrical projection was designed by Tom Patterson, US National
  * Park Service, in 2014, using Flex Projector. The polynomial equations for the
  * projection were developed by Bojan Savric, Oregon State University, in
  * collaboration with Tom Patterson and Bernhard Jenny, Oregon State University.
  *
- * Java reference algorithm implemented by Bojan Savric in JMapProjLib
- * project (file PattersonProjection.java)
+ * Java reference algorithm implemented by Bojan Savric in Java Map Projection
+ * Library (a Java port of PROJ.4) in the file PattersonProjection.java.
  *
- * Port to Proj.4 by Micah Cochran, 26 March 2016
+ * References:
+ *    Java Map Projection Library 
+ *       https://github.com/OSUCartography/JMapProjLib
+ * 
+ *    Patterson Cylindrical Projection
+ *       http://shadedrelief.com/patterson/
+ * 
+ *    Patterson, T., Savric, B., and Jenny, B. (2015). Cartographic Perspectives
+ *       (No.78). Describes the projection design and characteristics, and
+ *       developing the equations.    doi:10.14714/CP78.1270
+ *       http://dx.doi.org/10.14714/CP78.1270
+ * 
+ * Port to PROJ.4 by Micah Cochran, 26 March 2016
  */
 
 #define PJ_LIB__
-# include	<projects.h>
+# include   <projects.h>
 PROJ_HEAD(patterson, "Patterson Cylindrical") "\n\tCyl.";
 #define K1 1.0148
 #define K2 0.23185
@@ -26,15 +54,15 @@ PROJ_HEAD(patterson, "Patterson Cylindrical") "\n\tCyl.";
 
 FORWARD(s_forward); /* spheroid */
     double phi2;
-	(void) P;
+    (void) P;
     phi2 = lp.phi * lp.phi;
-	xy.x = lp.lam;
+    xy.x = lp.lam;
     xy.y = lp.phi * (K1 + phi2 * phi2 * (K2 + phi2 * (K3 + K4 * phi2)));
-	return (xy);
+    return (xy);
 }
 INVERSE(s_inverse); /* spheroid */
     double yc, tol, y2, f, fder;
-	(void) P;
+    (void) P;
     yc = xy.y;
     
     /* make sure y is inside valid range */
@@ -45,20 +73,20 @@ INVERSE(s_inverse); /* spheroid */
     }
     
     for (;;) { /* Newton-Raphson */
-		y2 = yc * yc;
-		f = (yc * (K1 + y2 * y2 * (K2 + y2 * (K3 + K4 * y2)))) - xy.y;
-		fder = C1 + y2 * y2 * (C2 + y2 * (C3 + C4 * y2));
-		yc -= tol = f / fder;
-		if (fabs(tol) < EPS11) {
-			break;
-		}
-	}
+        y2 = yc * yc;
+        f = (yc * (K1 + y2 * y2 * (K2 + y2 * (K3 + K4 * y2)))) - xy.y;
+        fder = C1 + y2 * y2 * (C2 + y2 * (C3 + C4 * y2));
+        yc -= tol = f / fder;
+        if (fabs(tol) < EPS11) {
+            break;
+        }
+    }
     lp.phi = yc;
     
     /* longitude */
-	lp.lam = xy.x;
-	
-	return (lp);
+    lp.lam = xy.x;
+    
+    return (lp);
 }
 FREEUP; if (P) pj_dalloc(P); }
 ENTRY0(patterson) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)
-- 
cgit v1.2.3