com.crs4.roodin.bayesian.SessionsLogger.java Source code

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Here is the source code for com.crs4.roodin.bayesian.SessionsLogger.java

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/*******************************************************************************
 * Copyright 2013 CRS4
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.crs4.roodin.bayesian;

// it's the old "server2.py" file for mobile. It contains the same functions.

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import android.util.Log;

/**
 * @author ICT/LBS Team - CRS4 Sardinia, Italy
 * 
 * Manage sessions and cell probs
 *
 */
public class SessionsLogger {

    //HashMap accetta chiavi nulle NON SINCRONIZZATA   (pi veloce dovrebbe andare bene nel nostro caso)
    //HashTable non accetta chiavi nulle SINCRONIZZATA pi sicura per multi-threading 

    Map<String, Map<String, Object>> sessions = new HashMap<String, Map<String, Object>>();

    /**
     * @param input JSONArray
     * @return double[] array from JSONArray
     */
    private double[] convertToArray(JSONArray input) {
        double[] output = new double[input.length()];

        try {
            for (int i = 0; i < input.length(); i++) {
                Double e = (Double) input.get(i);
                output[i] = e.doubleValue();
            }

        } catch (JSONException e1) {
            Log.e("ERRORE", "in convertJSONArray " + e1.getMessage());
        }

        return output;
    }

    /**
     * @param input
     * @return int[][] matrix from JSONArray 
     */
    private int[][] convertToMatrix(JSONArray input) {

        try {
            int rows = input.length();
            int cols = ((JSONArray) input.get(0)).length();

            Log.i("barred: ", "" + rows + "-" + cols);

            int[][] output = new int[rows][cols];

            for (int i = 0; i < rows; i++) {
                for (int j = 0; j < cols; j++) {
                    JSONArray e = (JSONArray) input.get(i);
                    Integer value = e.getInt(j);
                    output[i][j] = value.intValue();
                }
            }
            return output;

        } catch (JSONException e1) {
            Log.e("ERRORE", "in convertJSONArray " + e1.getMessage());
            return null;
        }
    }

    // save data and create probs
    /**
     * Create and save a new session for the user inside the building
     * 
     * @param sessionid the id of this session
     * @param startpos is the initial position
     * @param shape is the entire map shape 
     * @param barred the shape of barreds, usually a JSONArray of row,col as barred
     * @param ppm pixel per meter
     * @return the sessionid
     * @throws JSONException
     */
    public String saveSession(String sessionid, JSONArray startpos, JSONArray shape, JSONArray barred, int ppm)
            throws JSONException {

        Map<String, Object> session = new HashMap<String, Object>();
        Date date = new Date();

        session.put("id", sessionid);
        session.put("date_created", date.getDate()); //TODO la data  diversa da python
        session.put("probs", new double[shape.getInt(0)][shape.getInt(1)]); //numpy.zeros(shape),
        session.put("barred", convertToMatrix(barred));
        session.put("ppm", ppm);

        sessions.put(sessionid, session);

        System.out.println("session put: " + sessionid);

        return sessionid;
    }

    /**
     * Estimate the user position inside the shape
     * 
     * @param sessionid is the id of the session
     * @param heading 
     * @param radio is the radio string obtained from the wifi spots
     * @return estimate cell position of the user
     */
    public Cell estimatePos(String sessionid, double heading, String radio) { //TODO radio  string????

        Map<String, Object> session = sessions.get(sessionid);

        double[][] probs = (double[][]) session.get("probs");
        int[][] barred = (int[][]) session.get("barred");
        double[][] newprobs = Prob.evalProbs(probs, barred, heading); //static?? 
        Cell cell = Prob.estimatePos(probs); // row, col, deviance = prob.estimate_pos(probs)

        session.put("probs", newprobs); // session['probs'] = newprobs
        return cell;

    }

    /**
     * 
     * 
     * @param sessionid
     * @return current probabilities as JSONArray probs
     */
    public JSONArray getCurrentProbs(String sessionid) {
        Map<String, Object> session = sessions.get(sessionid);

        try {

            double[][] probsDouble = (double[][]) session.get("probs");

            JSONArray probsJSONArray = new JSONArray();

            for (int i = 0; i < probsDouble.length; i++) {
                JSONArray element = new JSONArray();
                for (int j = 0; j < probsDouble[0].length; j++) {
                    element.put(j, probsDouble[i][j]);
                }
                probsJSONArray.put(i, element);
            }

            return probsJSONArray;

        } catch (JSONException e) {
            Log.e("ERRORE", "in getCurrentProbs " + e.getMessage());

            e.printStackTrace();
            return null;
        }

    }

    /**
     * Sets the current probabilities
     * 
     * @param sessionid
     * @param row
     * @param col
     */
    public void setCurrentPos(String sessionid, int row, int col) {
        System.out.println("in SessionLogger setCurrentPos");
        System.out.println("current pos: " + row + " - " + col);

        Map<String, Object> session = sessions.get(sessionid);
        double[][] probs = (double[][]) session.get("probs");

        System.out.println("probs: " + probs.length + " " + probs[0].length);

        double[][] newprobs = new double[probs.length][probs[0].length];

        newprobs[row][col] = 1;

        session.put("probs", newprobs);

    }

}