/**
* @param source FeatureSource obtained from the shapefile of the area to redistrict
* @param galFile GAL file containing contiguity information about the area to redistrict
*/
public BlockGraph load(FeatureSource<SimpleFeatureType, SimpleFeature> source, String galFile) {
BlockGraph bg = new BlockGraph(source);
// Read GAL file
parseGal(bg, galFile);
// remove blocks with area 0
ArrayList<Block> toRemove = new ArrayList<Block>();
for (Block b : bg.getAllBlocks()) {
if (b.getArea() == 0) {
toRemove.add(b);
}
}
bg.removeAllBlocks(toRemove);
return bg;
}
/**
* Adds the edges to the input {@link BlockGraph}
*
* @param bg
* @param filename
*/
private void parseGal(BlockGraph bg, String filename) {
File galFile = new File(filename);
try {
FileInputStream fstream = new FileInputStream(galFile);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
int n_blocks = Integer.parseInt(br.readLine());
String currentline;
int line_num = 2;
for (int i = 0; i < n_blocks; i++, line_num++) {
// read current block id and number of neighbors
currentline = br.readLine();
if (currentline == null) {
System.err.println("Error in GAL file at line " + line_num);
System.exit(1);
}
StringTokenizer block_st = new StringTokenizer(currentline);
int current_block_id = -1;
int num_neighbors = -1;
try {
current_block_id = Integer.parseInt(block_st.nextToken());
num_neighbors = Integer.parseInt(block_st.nextToken());
} catch (NoSuchElementException e) {
System.err.println("Error in GAL file at line " + line_num);
System.exit(1);
}
Block currentBlock = bg.getBlock(current_block_id);
// now read neighbors ids
currentline = br.readLine();
if (currentline == null) {
System.err.println("Error in GAL file at line " + line_num);
System.exit(1);
}
StringTokenizer neighbor_st = new StringTokenizer(currentline);
for (int j = 0; j < num_neighbors; j++) {
int neighbor_id = -1;
try {
neighbor_id = Integer.parseInt(neighbor_st.nextToken());
} catch (NoSuchElementException e) {
System.err.println("Error in GAL file at line " + line_num);
System.exit(1);
}
// System.out.println("Adding " + neighbor_id +
// " to the neighbors of " + current_block_id);
currentBlock.neighbors.add(bg.getBlock(neighbor_id));
bg.getBlock(neighbor_id).neighbors.add(currentBlock);
}
}
in.close();
} catch (Exception e) { // Catch exception if any
System.err.println("Error: " + e.getMessage());
e.printStackTrace();
}
}