AFRStream.java

/**
 * Copyright 2012 Kevin J. Jones (http://www.kevinjjones.co.uk)
 *
 * 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 uk.co.kevinjjones.vehicle;

import uk.co.kevinjjones.Log;
import uk.co.kevinjjones.model.*;

/**
 * AFR virtual stream.
 */
public class AFRStream extends StreamBase {

    public final static int AFR = 1;
    public final static int LAMBDA = 2;
    public final static String AFR_NAME = "AFR";
    public final static String LAMBDA_NAME = "LAMBDA";

    public static String name(int index) {
        switch (index) {
            case AFR:
                return AFR_NAME;
            case LAMBDA:
                return LAMBDA_NAME;
        }
        return null;
    }
    private static int _isAFR = 0;

    private static boolean isAFR(ROStream s) {
        if (_isAFR != 0) {
            return _isAFR == AFR;
        }

        DoubleSampler ds = new DoubleSampler(0.0, 20.0, 200);
        Distribution<Double> d = new Distribution<Double>(ds);
        d.sample(s.toArray());

        // If Lambda we should not see samples >2
        int b = 20;
        for (; b < 200; b++) {
            if (d.samples(b) > 0) {
                break;
            }
        }
        if (b >= 200) {
            _isAFR = LAMBDA;
        } else {
            _isAFR = AFR;
        }

        return _isAFR == 1;
    }
    private View _view;
    private int _type = -1;
    private ROStream _stream;
    private int _streamType;

    public AFRStream() {
    }

    @Override
    public void setView(View view, Object arg, ParamHandler handler, WithError<Boolean, BasicError> ok) {
        _view = view;
        _type = ((Integer) arg).intValue();
        assert (_type >= 1 && _type <= 2);

        _stream = _view.getStream(Log.LAMB_STREAM);
        if (_stream == null) {
            ok.setValue(false);
        } else {
            _stream.setMeta("hide", "true");
            _streamType = isAFR(_stream) ? AFR : LAMBDA;
        }
    }

    @Override
    public String name() {
        return name(_type);
    }

    @Override
    public String description() {
        return name();
    }

    @Override
    public String axis() {
        return name(_type);
    }

    @Override
    public String units() {
        return null; // Unknown
    }

    @Override
    public int size() {
        return _view.getStream(Log.TIME_STREAM).size();
    }

    @Override
    public double getNumeric(int position) throws NumberFormatException {
        double v = _stream.getNumeric(position);
        if (_type == AFR && _streamType != AFR) {
            return v * 14.7;
        } else if (_type == LAMBDA && _streamType != LAMBDA) {
            return v / 14.7;
        }
        return v;
    }
}