arow.d

import arow;
import std.stdio;
import std.random;
import std.string;
import std.conv;
import std.file;
import std.stream;

struct example {
  int label;
  double[int] features;

  @safe nothrow {
    this(int label, double[int] features) {
      this.label = label;
      this.features = features;
    }
  }
}

double[int] parseLine(string line) {
  immutable string delim_value = ":";
  immutable string delim_cols = " ";

  string[] columns = line.split(delim_cols);

  double[int] f;

  for(int i = 1; i < columns.length; i++) {
    string[] arr = columns[i].split(delim_value);

    if(arr.length != 2)
      continue;

    assert(arr != null);
    assert(arr.length == 2);

    auto key = to!int(arr[0]);
    auto val = to!double(arr[1]);

    f[key] = val;
  }

  return f;
}

/*
example[] readDataIris(string filename){
  Stream file = new BufferedFile(filename);
  size_t num_lines = 0;

  example[] data;

  foreach (char[] _line; file) {

    string line = cast(string)_line;

    if (line.length == 0) continue;
    if (line[0] == '#') continue;

    assert(line[0] == '1' || line[0] == '2' || line[0] == '3');

    string[] columns = line.split(",");
    double[int] vec = parseLine(line);
    vec[0] = to!double(columns[1]);
    vec[1] = to!double(columns[2]);
    vec[2] = to!double(columns[3]);
    example ex = example(to!int(columns[0]) - 1, vec);

    data ~= ex;
  }

  file.close();

  return data;
}
*/

example[] readDataMulti(string filename){
  Stream file = new BufferedFile(filename);
  size_t num_lines = 0;

  example[] data;

  foreach (char[] _line; file) {

    string line = cast(string)_line;

    if (line.length == 0) continue;
    if (line[0] == '#') continue;

    int label = to!int(line.split(" ")[0]) - 1;
    double[int] vec = parseLine(line);

    if(vec != null) {
      example ex = example(label, vec);

      assert(vec != null);
      assert(ex.features != null);

      data ~= ex;

    }
  }

  file.close();

  return data;
}

example[] readData(string filename){
  Stream file = new BufferedFile(filename);
  size_t num_lines = 0;

  example[] data;

  foreach (char[] _line; file) {

    string line = cast(string)_line;

    if (line.length == 0) continue;
    if (line[0] == '#') continue;

    assert(line[0] == '-' || line[0] == '+');

    int label = line[0] == '+' ? +1 : -1;
    double[int] vec = parseLine(line);

    if(vec != null) {
      example ex = example(label, vec);

      assert(vec != null);
      assert(ex.features != null);
      assert(ex.label == -1 || ex.label == +1);

      data ~= ex;

    }
  }

  file.close();

  return data;
}

void main(string[] args) {
  immutable uint dimension = 62062;
  
	int num_class = 20;

  Arow arow[];
	arow.length = num_class;
	for(auto i = 0; i < num_class; i++) arow[i] = new Arow(dimension, 0.1);

  example[] data = readDataMulti("news20.scale");
  data.randomShuffle();

  int i;
  int num_train = 10000;
  for(i = 0; i < num_train; i++) {
    int label = data[i].label;

    for(auto j = 0; j < num_class; j++) {
			/*
			if(data[i].label == j)
				arow[j].update(data[i].features, 1);
			else if(uniform(0,2) == 0)
				arow[j].update(data[i].features, -1);
			*/
      arow[j].update(data[i].features, data[i].label == j ? 1 : -1);
    }
  }

  int correct = 0;
  for(; i < data.length; i++) {
		int result;
		double max_distance = -double.infinity;
    for(auto j = 0; j < num_class; j++) {
      auto d = arow[j].getMargin(data[i].features);
			if(d > max_distance) {
				result = j;
				max_distance = d;
			}
    }
		if(result == data[i].label) correct++;
  }

  writeln(correct, "/", (cast(double)data.length - num_train));
  writeln(correct / (cast(double)data.length - num_train));
}

/+
void main(string[] args) {
  immutable uint dimension = 5;
  
  Arow arow[3];
  arow[0] = new Arow(dimension, 0.1);
  arow[1] = new Arow(dimension, 0.1);
  arow[2] = new Arow(dimension, 0.1);

  example[] data = readDataMulti("iris.scale");

  data.randomShuffle();

  int i;
  int num_train = 100;
  for(i = 0; i < num_train; i++) {
    int label = data[i].label;

    for(auto j = 0; j < 3; j++) {
			
			if(data[i].label == j)
				arow[j].update(data[i].features, 1);
			else if(uniform(0,2) == 0)
				arow[j].update(data[i].features, -1);
			
      //arow[j].update(data[i].features, data[i].label == j ? 1 : -1);
    }
  }

  int correct = 0;
  for(; i < data.length; i++) {
    write(data[i].label, ": ");
		int result;
		double max_distance = -double.infinity;
    for(auto j = 0; j < 3; j++) {
      auto d = arow[j].getMargin(data[i].features);
			if(d > max_distance) {
				result = j;
				max_distance = d;
			}
      write(d, ", ");
    }
    writeln("->", result);
		if(result == data[i].label) correct++;
  }

  writeln(correct, "/", (cast(double)data.length - num_train));
  writeln(correct / (cast(double)data.length - num_train));
}
+/