Changeset 33853

Timestamp:

2020-01-21T21:58:29+13:00 (4 years ago)

Author:

ak19

Message:

Handling map coordinates that are horizontally excessive (beyond allowed longitudes of -180 and 180). With the code now dealing with both points too far north (beyond allowed latitude of 90) and too far east or west, the code generating the geojson map data can now deal with very large count values as when dealing with numPages rather than the smaller numSites.

File:

• other-projects/maori-lang-detection/src/org/greenstone/atea/CountryCodeCountsMapData.java (modified) (4 diffs)

other-projects/maori-lang-detection/src/org/greenstone/atea/CountryCodeCountsMapData.java

@@ -12 +12 @@
 import java.util.List;
 import java.util.Map;
+
+//import java.lang.Math; //automatically imported apparently
 
 import org.apache.commons.csv.*;
@@ -328 +330 @@
 
     // create rectangular "histogram" for each country code
-    private Geometry toPolygon(JsonObject json, int count, int HISTOGRAM_WIDTH) {
+    private Geometry toPolygon(JsonObject json, final int count, final int HISTOGRAM_WIDTH) {
     int half_width = HISTOGRAM_WIDTH/2;
     double vertical_factor = 1.0;
     
-    Double lng = json.get("lng").getAsDouble();
-    Double lat = json.get("lat").getAsDouble();
+    final Double lng = json.get("lng").getAsDouble();
+    final Double lat = json.get("lat").getAsDouble();
 
     String countryCode = json.get("countrycode").getAsString();
@@ -345 +347 @@
     // to grow northwards.
     Double north = lat + (vertical_factor * count);
+    
     while (north > 90) {
         // recalculate north after decreasing histogram's vertical growth
@@ -355 +358 @@
     Double west = lng - half_width;
     Double south = lat;
+        
+    // Check if we're dealing with very large numbers, in which case, we can have follow off the longitude edges
+    // Max longitude values are -180 to 180. So a max of 360 units between them.
+    if((east + Math.abs(west)) > 360 || east > 180 || west < -180) {
+        half_width = HISTOGRAM_WIDTH/2; // reset half_width
+        
+        double v_tmp_count = Math.sqrt(count);
+        double h_tmp_count = Math.floor(v_tmp_count);
+        v_tmp_count = Math.ceil(v_tmp_count);
+
+        /*
+        System.err.println("HERE, count = " + count);
+        System.err.println("HERE, v = " + v_tmp_count);
+        System.err.println("HERE, h = " + h_tmp_count);
+        System.err.println("HERE, lat = " + lat);
+        System.err.println("HERE, lng = " + lng + "\n");
+        */
+
+        north = lat + v_tmp_count;
+        south = lat;
+        east = lng + (h_tmp_count/2 * half_width); // a certain width, half_width, represents one unit in the x axis
+        west = lng - (h_tmp_count/2 * half_width);
+
+        if(north > 90) {
+        // centre vertically on lat
+        north = lat + (v_tmp_count/2);
+        south = lat - (v_tmp_count/2);
+        }
+
+        if(west < -180.0) {
+        double h_diff = lng - 180.0; // the country's longitude (lng) is h_diff from the western edge
+        west = 180.0; // maximise western edge
+        east = h_tmp_count - h_diff/half_width;// then grow the remainder of h_tmp_count in the opposite (eastern) direction
+        }       
+        else if(east > 180.0) {
+        double h_diff = 180.0 - lng; // the country's longitude (lng) is h_diff from the eastern edge
+        east = 180.0; // maximise eastern edge
+        west = -1 * (h_tmp_count - (h_diff/half_width)); // then grow the remainder of h_tmp_count in the opposite (western) direction
+        }
+        
+        // CAN'T centre on country, (lat,lng), as we don't know whether either of lat or lng has gone past the edge
+        //north = lat + (v_tmp_count/2);
+        //south = lat - (v_tmp_count/2);
+        //east = lng + (h_tmp_count/2);
+        //west = lng - (h_tmp_count/2);
+        
+        // hopefully we don't exceed +90/-90 lat and +/-180 longitude
+        // "Longitude is in the range -180 and +180 specifying coordinates west and east of the Prime Meridian, respectively.
+        // For reference, the Equator has a latitude of 0°, the North pole has a latitude of 90° north (written 90° N or +90°),
+        // and the South pole has a latitude of -90°."
+
+        /*
+        System.err.println("north = " + north);
+        System.err.println("south = " + south);
+        System.err.println("east = " + east);
+        System.err.println("west = " + west);
+        */
+    }
     
     List<List<Position>> outerList = new LinkedList<List<Position>>();