I make maps with _direction_ and MAGNITUDE

I added a few more vector inputs that I've been wanting for some time. My Tissot one I actually don't love, but it is based heavily on Eric Gaba's Tissot maps that are all over Wikipedia that I want to replace because they lack indicatrices in the most important locations: the poles and the prime meridian. After I fix Wikipedia, I might make a new one without a graticule and with more indicatrices.
I also made my program slightly better at loading new SVG maps and fixed Landmasses to not have a weird broken Antarctica.

README.md

@@ -32,12 +32,13 @@ For some examples, check out the `output` folder. For more information, go to [j
 
 ## Credits
 While I wrote all of the code in this repository myself, and I created several of the simpler images from scratch, other people did help. Here's a comprehensive list.
-* **The NASA** for [Basic.png](https://visibleearth.nasa.gov/view.php?id=57730), [Satellite.jpg](https://visibleearth.nasa.gov/view.php?id=57752), and [Altitude.png](https://asterweb.jpl.nasa.gov/gdem.asp)
-* **Tom Patterson** for [Pastel.jpg](http://www.shadedrelief.com/natural3/pages/textures.html) and [Rivers.png](http://www.shadedrelief.com/natural3/pages/extra.html)
-* **RokerHRO** for [the indicatrix layer of Tissot.jpg](https://commons.wikimedia.org/wiki/File:Tissot_10deg.png)
-* **Crates** for [Landmasses.svg and the landmass layer of Basic.svg](https://commons.wikimedia.org/wiki/File:World_map_blank_without_borders.svg)
-* **The CIA** for [Political.svg and Political.png](https://commons.wikimedia.org/wiki/File:BlankMap-World6-Equirectangular.svg).
-* **The Apache Commons** for their [complex mathematics code](https://commons.apache.org/proper/commons-math/)
-* **Technische Universität Berlin** for their [complex mathematics code](http://www3.math.tu-berlin.de/jtem/ellipticFunctions/)
-* **AuthaGraph Co., Ltd.** for their [vague information about their map projection](http://www.authagraph.com/projects/description/%E3%80%90%E4%BD%9C%E5%93%81%E8%A7%A3%E8%AA%AC%E3%80%91%E8%A8%98%E4%BA%8B01/?lang=en), which inspired several of my own.
-* **Wikipedia** for their [impressive collection of map projection information and equations](https://en.wikipedia.org/wiki/List_of_map_projections)
+* **The NASA** for [Basic.png](https://visibleearth.nasa.gov/view.php?id=57730), [Satellite.jpg](https://visibleearth.nasa.gov/view.php?id=57752), and [Altitude.png](https://asterweb.jpl.nasa.gov/gdem.asp),
+* **Tom Patterson** for [Pastel.jpg](http://www.shadedrelief.com/natural3/pages/textures.html) and [Rivers.png](http://www.shadedrelief.com/natural3/pages/extra.html),
+* **RokerHRO** for [the indicatrix layer of Tissot.jpg](https://commons.wikimedia.org/wiki/File:Tissot_10deg.png),
+* **Crates** for [Landmasses.svg](https://commons.wikimedia.org/wiki/File:World_map_blank_without_borders.svg), which I adapted into Basic.svg and Tissot.svg,
+* **The CIA** for [Political.svg and Political.png](https://commons.wikimedia.org/wiki/File:BlankMap-World6-Equirectangular.svg),
+* **The Apache Commons** for their [complex mathematics code](https://commons.apache.org/proper/commons-math/),
+* **Technische Universität Berlin** for their [complex mathematics code](http://www3.math.tu-berlin.de/jtem/ellipticFunctions/),
+* **Gene Keyes** for his [impressively in-depth and open documentation of his map projection](http://www.genekeyes.com/CKOG-OOo/7-CKOG-illus-&-coastline.html),
+* **AuthaGraph Co., Ltd.** for their [vague information about their map projection](http://www.authagraph.com/projects/description/%E3%80%90%E4%BD%9C%E5%93%81%E8%A7%A3%E8%AA%AC%E3%80%91%E8%A8%98%E4%BA%8B01/?lang=en), which inspired several of my own, and
+* **Wikipedia** for their [substantial collection of map projection information and equations](https://en.wikipedia.org/wiki/List_of_map_projections).

src/maps/Projection.java

@@ -433,19 +433,16 @@ public abstract class Projection {
 				lonf = lon0;
 		}
 		else if (Math.sin(lon1) > 0)
-			lonf = lon0 +
-					Math.acos(innerFunc);
+			lonf = lon0 + Math.acos(innerFunc);
 		else
-			lonf = lon0 -
-					Math.acos(innerFunc);
+			lonf = lon0 - Math.acos(innerFunc);
 		
 		if (Math.abs(lonf) > Math.PI)
 			lonf = Math2.floorMod(lonf+Math.PI, 2*Math.PI) - Math.PI;
 		
 		double thtf = pole[2];
 		
-		double[] output = {latf, lonf, thtf};
-		return output;
+		return new double[] {latf, lonf, thtf};
 	}
 	
 	

src/utils/SVGMap.java

@@ -81,7 +81,7 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 			
 			@Override
 			public void startElement(
-					String uri, String localName, String qName, Attributes attributes) {
+					String uri, String localName, String qName, Attributes attributes) throws SAXException {
 				currentFormatString += "<"+qName;
 				
 				if (attributes.getIndex("transform") >= 0)
@@ -89,8 +89,13 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 				else
 					parseTransform();
 				
-				if (qName.equals("path"))
-					parsePath(attributes.getValue("d"));
+				if (qName.equals("path")) {
+					try {
+						parsePath(attributes.getValue("d"));
+					} catch (Exception e) {
+						throw new SAXException(e.getLocalizedMessage(), null);
+					}
+				}
 				
 				if (qName.equals("svg")) {
 					parseViewBox(attributes);
@@ -181,7 +186,7 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 				transformStack.push(new double[] {xScale, yScale, xTrans, yTrans});
 			}
 			
-			private void parsePath(String d) {
+			private void parsePath(String d) throws Exception {
 				currentFormatString += " d=\"";
 				format.add(currentFormatString);
 				paths.add(new Path(d, transformStack.peek(), minX, minY, width, height));
@@ -259,12 +264,12 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 			super();
 		}
 		
-		public Path(String d, double vbWidth, double vbHeight) {
+		public Path(String d, double vbWidth, double vbHeight) throws Exception {
 			this(d, new double[] {1,1,0,0}, 0, 0, vbWidth, vbHeight);
 		}
 		
 		public Path(String d, double[] transform,
-				double vbMinX, double vbMinY, double vbWidth, double vbHeight) {
+				double vbMinX, double vbMinY, double vbWidth, double vbHeight) throws Exception { //I don't know if this is bad coding practice, but I don't really want to find a way to gracefully catch all possible errors into some more specific Exception class
 			super();
 			
 			int i = 0;
@@ -276,6 +281,7 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 					i ++;
 					argString += d.charAt(i);
 				}
+				argString = argString.replaceAll("([0-9\\.])-", "$1,-"); //this is necessary because some Adobe products leave out delimiters between negative numbers
 				i ++;
 				
 				String[] argStrings;
@@ -288,11 +294,11 @@ public class SVGMap implements Iterable<SVGMap.Path> {
 					argStrings = new String[] {argStrings[3], argStrings[4]};
 				}
 				if (type == 'h' || type == 'H' || type == 'v' || type == 'V') { //convert these to 'L'
-					final int chgIdx = (type%32 == 8) ? 0 : 1;
+					final int direcIdx = (type%32 == 8) ? 0 : 1;
 					args = new double[] {last[0], last[1]};
-					if (type <= 'Z') 	args[chgIdx] = Double.parseDouble(argStrings[0]); //uppercase (absolute)
-					else 				args[chgIdx] += Double.parseDouble(argStrings[0]); //lowercase (relative)
-					last[chgIdx] = args[chgIdx];
+					if (type <= 'Z') 	args[direcIdx] = Double.parseDouble(argStrings[0]); //uppercase (absolute)
+					else 				args[direcIdx] += Double.parseDouble(argStrings[0]); //lowercase (relative)
+					last[direcIdx] = args[direcIdx];
 					type = 'L';
 				}
 				else {

src/zupplementary python/input_generator.py

@@ -0,0 +1,123 @@
+import math
+import numpy as np
+
+PHI = (math.sqrt(5)+1)/2
+ATH = math.atan(1/2)
+
+IND_NUM = 120
+IND_RAD = 500/6371
+
+
+def obliquify(lat1, lon1, lat0, lon0):
+	""" go from relative to absolute coordinates """
+	latf = math.asin(math.sin(lat0)*math.sin(lat1) - math.cos(lat0)*math.cos(lon1)*math.cos(lat1))
+	innerFunc = math.sin(lat1)/math.cos(lat0)/math.cos(latf) - math.tan(lat0)*math.tan(latf)
+	if lat0 == math.pi/2: # accounts for special case when lat0 = pi/2
+		lonf = lon1+lon0
+	elif lat0 == -math.pi/2: # accounts for special case when lat0 = -pi/2
+		lonf = -lon1+lon0 + math.pi
+	elif abs(innerFunc) > 1: # accounts for special case when cos(lat1) -> 0
+		if (lon1 == 0 and lat1 < -lat0) or (lon1 != 0 and lat1 < lat0):
+			lonf = lon0 + math.pi
+		else:
+			lonf = lon0
+	elif math.sin(lon1) > 0:
+		lonf = lon0 + math.acos(innerFunc)
+	else:
+		lonf = lon0 - math.acos(innerFunc)
+		
+	return latf, lonf
+
+
+def plot(coords):
+	tag = '      <path d="'
+	for phi, lam in coords:
+		tag += 'L{:.3f},{:.3f} '.format(2*math.degrees(lam), 2*math.degrees(phi)+180)
+	tag += 'Z"/>'
+	print(tag.replace('L', 'M', 1).replace('.000',''))
+
+
+def plot_orthodrome(phi0, lam0, tht0):
+	tag = '    <path d="'
+	for p in range(90, -90, -1):
+		phin, lamn = obliquify(math.radians(p), tht0, phi0, lam0)
+		tag += 'L{:.3f},{:.3f} '.format(math.degrees(lamn), math.degrees(phin))
+	for p in range(-90, 90, 1):
+		phin, lamn = obliquify(math.radians(p), tht0+math.pi, phi0, lam0)
+		tag += 'L{:.3f},{:.3f} '.format(math.degrees(lamn), math.degrees(phin))
+	tag += 'Z"/>'
+	print(tag.replace('L', 'M', 1))
+
+
+def plot_indicatrix(phi0, lam0, r):
+	tag = '      <path d="'
+	for l in range(0, 360, 360//IND_NUM):
+		phin, lamn = obliquify(math.pi/2-r, math.radians(l), phi0, lam0)
+		tag += 'L{:.3f},{:.3f} '.format(2*math.degrees(lamn), 2*math.degrees(phin)+180)
+	tag += 'Z"/>'
+	print(tag.replace('L', 'M', 1).replace('.000',''))
+
+
+def plot_side_indicatrix(phi0, r):
+	tag0 = '      <path d="'
+	for l in range(0, 181, 360//IND_NUM):
+		phin, lamn = obliquify(math.pi/2-r, math.radians(l), phi0, 0)
+		tag0 += 'L{:.3f},{:.3f} '.format(2*math.degrees(lamn), 2*math.degrees(phin)+180)
+	tag1 = ''
+	for l in range(180, 361, 360//IND_NUM):
+		phin, lamn = obliquify(math.pi/2-r, math.radians(l), phi0, 0)
+		tag1 += 'L{:.3f},{:.3f} '.format(2*math.degrees(lamn)+720, 2*math.degrees(phin)+180)
+	tag1 += 'Z"/>'
+	print(tag0.replace('L', 'M', 1).replace('.000','') + tag1.replace('L', 'M', 1).replace('.000',''))
+
+
+def plot_pole_indicatrix(north, r):
+	if north:
+		yp, yr = 360, 360-2*math.degrees(r)
+	else:
+		yp, yr = 0, 2*math.degrees(r)
+
+	tag = '      <path d="'
+	tag += 'M{},{} '.format(0, yp)
+	for x in range(0, 721, 360//IND_NUM):
+		tag += 'L{},{:.3f} '.format(x, yr)
+	tag += 'L{},{} Z"/>'.format(720, yp)
+	print(tag)
+
+
+def plot_meridian(lamd):
+	tag = '      <path d="'
+	for phi in range(-90, 91):
+		tag += 'L{},{} '.format(2*lamd, 2*phi + 180)
+	tag += '"/>'
+	print(tag.replace('L', 'M', 1))
+
+
+def plot_parallel(phid):
+	tag = '      <path d="'
+	for lam in range(0, 361):
+		tag += 'L{},{} '.format(2*lam, 2*phid + 180)
+	tag += '"/>'
+	print(tag.replace('L', 'M', 1))
+
+
+if __name__ == '__main__':
+	# for l in range(0, 180, 36):
+	# 	plot_orthodrome(math.pi/2, 0, math.radians(l))
+	# for l in range(0, 360, 72):
+	# 	plot_orthodrome(ATH, math.radians(l), math.pi*.4)
+	# 	plot_orthodrome(ATH, math.radians(l), math.pi*.8)
+
+	plot_pole_indicatrix(False, IND_RAD)
+	for y in [60, 30, 0, -30, -60]:
+		for x in range(0, 360, 30):
+			# if x == 0:
+			# 	plot_side_indicatrix(math.radians(y), math.pi/36)
+			# else:
+				plot_indicatrix(math.radians(y), math.radians(x), IND_RAD)
+	plot_pole_indicatrix(True, IND_RAD)
+
+	# for x in range(0, 361, 10):
+	# 	plot_meridian(x)
+	# for y in range(-80, 90, 10):
+	# 	plot_parallel(y)