Android Distance Calculate calculateEte(boolean useBearing, double distance, double speed, double bearing, double heading)

Description

Fetch the estimate travel time to the indicated target

License

Open Source License

Parameter

Parameter	Description
distance	- how far to the target
speed	- how fast we are moving
bearing	- direction to target
heading	- direction of movement

Return

String - "HH:MM" or "MM.SS" time to the target

Declaration

public static String calculateEte(boolean useBearing, double distance,
        double speed, double bearing, double heading) 

Method Source Code

//package com.java2s;

import java.util.Locale;

import android.text.format.Time;

public class Main {
    /***//from w w  w  .  ja v a 2 s.  c  om
     * Fetch the estimate travel time to the indicated target
     * @param distance - how far to the target
     * @param speed - how fast we are moving
     * @param bearing - direction to target
     * @param heading - direction of movement
     * @return String - "HH:MM" or "MM.SS" time to the target
     */
    public static String calculateEte(boolean useBearing, double distance,
            double speed, double bearing, double heading) {

        // If no speed, then return the empty display value
        if (0 == speed) {
            return "--:--";
        }

        // Fetch the eteRaw value
        Time eteRaw = fetchRawEte(useBearing, distance, speed, bearing,
                heading);

        // If an invalid eteRaw, then return the empty display value
        if (null == eteRaw) {
            return "--:--";
        }

        // Break the eteRaw out into hours and minutes
        int eteHr = eteRaw.hour;
        int eteMin = eteRaw.minute;
        int eteSecond = eteRaw.second;

        // Hours greater than 99 are not displayable
        if (eteHr > 99) {
            return "XX:XX";
        }

        // If hours is non zero then return HH:MM
        if (eteHr > 0) {
            // Format the hours and minutes en router
            String hr = String.format(Locale.getDefault(), "%02d", eteHr);
            String min = String.format(Locale.getDefault(), "%02d", eteMin);

            // Build the string for return
            return hr + ":" + min;
        }

        // Hours is zero, so return MM.SS
        String min = String.format(Locale.getDefault(), "%02d", eteMin);
        String sec = String.format(Locale.getDefault(), "%02d", eteSecond);

        // Build the string for return
        return min + "." + sec;

    }

    /***
     * Fetch the raw estimated time enroute given the input parameters
     * @param distance - how far to the target
     * @param speed - how fast we are moving
     * @param bearing - direction to target
     * @param heading - direction of movement
     * @return int value of HR * 100 + MIN for the ete, -1 if not applicable
     */
    private static Time fetchRawEte(boolean useBearing, double distance,
            double speed, double bearing, double heading) {
        double xFactor = 1;
        if (useBearing) {
            // We can't assume that we are heading DIRECTLY for the destination, so 
            // we need to figure out the multiply factor by taking the COS of the difference
            // between the bearing and the heading.
            double angDif = angularDifference(heading, bearing);

            // If the difference is 90 or greater, then ETE means nothing as we are not
            // closing on the target
            if (angDif >= 90)
                return null;

            // Calculate the actual relative speed closing on the target
            xFactor = Math.cos(angDif * Math.PI / 180);
        }

        // Calculate the travel time in seconds
        double eteTotal = (distance / (speed * xFactor)) * 3600;

        // Allocate an empty time object
        Time ete = new Time();

        // Extract the hours
        ete.hour = (int) (eteTotal / 3600); // take whole int value as the hours
        eteTotal -= (ete.hour * 3600); // Remove the hours that we extracted

        // Convert what's left to fractional minutes
        ete.minute = (int) (eteTotal / 60); // Get the int value as the minutes now
        eteTotal -= (ete.minute * 60); // remove the minutes we just extracted

        // What's left is the remaining seconds 
        ete.second = Math.round((int) eteTotal); // round as appropriate

        // Account for the seconds being 60
        if (ete.second >= 60) {
            ete.minute++;
            ete.second -= 60;
        }

        // account for the minutes being 60
        if (ete.minute >= 60) {
            ete.hour++;
            ete.minute -= 60;
        }

        // Time object is good to go now
        return ete;
    }

    /** Calculate the absolute angular difference between the two headings
     * 
     * @param hdg angle 1 in degrees (typically the heading)
     * @param brg angle 2 in degrees (typically the bearing)
     * @return difference between hdg and brg in degrees
     */
    public static double angularDifference(double hdg, double brg) {
        double absDiff = Math.abs(hdg - brg);
        if (absDiff > 180) {
            return 360 - absDiff;
        }
        return absDiff;
    }
}

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4. hammingDistance(String sourceHashCode, String hashCode)
5. getMessageForDistance(long distance)
6. fetchRawEte(boolean useBearing, double distance, double speed, double bearing, double heading)
7. distance(double lat1, double lon1, double lat2, double lon2, char unit)
8. computeSpeed(int distance, long duration)
9. getClosestStore(ArrayList storeIds, SparseArray distanceMap)