I've opted for using an SVG with each county as a shape within the SVG. I have all the names of the counties, along with some data, stored in a 2D array. The names in the array correspond to the names of the county shapes in the SVG.

I would like to create all the county shapes using a loop, and then I can change their colours etc. to represent data. I've tried to do this by creating a PShape array and making each shape in the SVG an object using a loop with getChild(), but it doesn't work...

2. PShape UKmap;
3. PShape[] counties = new PShape[49];
4. int x = 40;
5. String lines[];
6. String [][] csv;
7. int csvWidth=0;
8. int mapX = width/2+250;
9. int mapY = height/2+50;
10. int mapSize = 600;
11. 
    
12. void setup() {
13.   size(1280, 800);
14.   UKmap = loadShape("UK_counties.svg");
15.   stroke(0);
16.   fill(0, 150, 0);
17.   smooth();
18.   shapeMode(CENTER);
19.   //for importing csv files into a 2d array
20.   //by che-wei wang
21.   lines = loadStrings("UK counties.csv");
22.   //calculate max width of csv file
23.   for (int i=0; i < lines.length; i++) {
24.     String [] chars=split(lines[i], ',');
25.     if (chars.length>csvWidth) {
26.       csvWidth=chars.length;
27.     }
28.   }
29. 
    
30.   //create csv array based on # of rows and columns in csv file
31.   csv = new String [lines.length][csvWidth];
32. 
    
33.   //parse values into 2d array
34.   for (int i=0; i < lines.length; i++) {
35.     String [] temp = new String [lines.length];
36.     temp= split(lines[i], ',');
37.     for (int j=0; j < temp.length; j++) {
38.       csv[i][j]=temp[j];
39.     }
40.   }
41.   
42.   //draw the country map
43.   shape(UKmap, mapX, mapY, mapSize, mapSize);
44.   //create each county
45.   for (int i=1; i < lines.length+1; i++) {
46.     //    counties[i] = new PShape();
47.     counties[i] = UKmap.getChild(csv[i][0]);
48.     //colour each county according to pop. density
49.     fill(map(int(csv[i][2]), 0, 9000, 255, 0), 0, 0);
50.     //draw the counties
51.     shape(counties[i], mapX, mapY, mapSize, mapSize);
52.   }
53. }
54. 
    
55. void draw() {
56. }

This gives me a NullPointerException, and I presume that's because the county shapes aren't being created. How can I name each one using the names from my array?