Merge branch 'branch-1.8' into debian

1 files changed, 307 insertions, 0 deletions

diff --git a/altoslib/AltosTimeSeries.java b/altoslib/AltosTimeSeries.java
new file mode 100644
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+++ b/altoslib/AltosTimeSeries.java
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+/*
+ * Copyright © 2017 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+package org.altusmetrum.altoslib_12;
+
+import java.util.*;
+
+public class AltosTimeSeries implements Iterable<AltosTimeValue>, Comparable<AltosTimeSeries> {
+	public String			label;
+	public AltosUnits		units;
+	ArrayList<AltosTimeValue>	values;
+
+	public int compareTo(AltosTimeSeries other) {
+		return label.compareTo(other.label);
+	}
+
+	public void add(AltosTimeValue tv) {
+		values.add(tv);
+	}
+
+	public void add(double time, double value) {
+		add(new AltosTimeValue(time, value));
+	}
+
+	public AltosTimeValue get(int i) {
+		return values.get(i);
+	}
+
+	private double lerp(AltosTimeValue v0, AltosTimeValue v1, double t) {
+		/* degenerate case */
+		if (v0.time == v1.time)
+			return (v0.value + v1.value) / 2;
+
+		return (v0.value * (v1.time - t) + v1.value * (t - v0.time)) / (v1.time - v0.time);
+	}
+
+	private int after_index(double time) {
+		int	lo = 0;
+		int	hi = values.size() - 1;
+
+		while (lo <= hi) {
+			int mid = (lo + hi) / 2;
+
+			if (values.get(mid).time < time)
+				lo = mid + 1;
+			else
+				hi = mid - 1;
+		}
+		return lo;
+	}
+
+	/* Compute a value for an arbitrary time */
+	public double value(double time) {
+		int after = after_index(time);
+		double ret;
+
+		if (after == 0)
+			ret = values.get(0).value;
+		else if (after == values.size())
+			ret = values.get(after - 1).value;
+		else {
+			AltosTimeValue b = values.get(after-1);
+			AltosTimeValue a = values.get(after);
+			ret = lerp(b, a, time);
+		}
+		return ret;
+	}
+
+	/* Find the value just before an arbitrary time */
+	public double value_before(double time) {
+		int after = after_index(time);
+
+		if (after == 0)
+			return values.get(0).value;
+		return values.get(after-1).value;
+	}
+
+	/* Find the value just after an arbitrary time */
+	public double value_after(double time) {
+		int after = after_index(time);
+
+		if (after == values.size())
+			return values.get(after-1).value;
+		return values.get(after).value;
+	}
+
+	public double time_of(double value) {
+		double	last = AltosLib.MISSING;
+		for (AltosTimeValue v : values) {
+			if (v.value >= value)
+				return v.time;
+			last = v.time;
+		}
+		return last;
+	}
+
+	public int size() {
+		return values.size();
+	}
+
+	public Iterator<AltosTimeValue> iterator() {
+		return values.iterator();
+	}
+
+	public AltosTimeValue max() {
+		AltosTimeValue max = null;
+		for (AltosTimeValue tv : values)
+			if (max == null || tv.value > max.value)
+				max = tv;
+		return max;
+	}
+
+	public AltosTimeValue max(double start_time, double end_time) {
+		AltosTimeValue max = null;
+		for (AltosTimeValue tv : values) {
+			if (start_time <= tv.time && tv.time <= end_time)
+				if (max == null || tv.value > max.value)
+					max = tv;
+		}
+		return max;
+	}
+
+	public AltosTimeValue min() {
+		AltosTimeValue min = null;
+		for (AltosTimeValue tv : values) {
+			if (min == null || tv.value < min.value)
+				min = tv;
+		}
+		return min;
+	}
+
+	public AltosTimeValue min(double start_time, double end_time) {
+		AltosTimeValue min = null;
+		for (AltosTimeValue tv : values) {
+			if (start_time <= tv.time && tv.time <= end_time)
+				if (min == null || tv.value < min.value)
+					min = tv;
+		}
+		return min;
+	}
+
+	public AltosTimeValue first() {
+		return values.get(0);
+	}
+
+	public AltosTimeValue last() {
+		return values.get(values.size() - 1);
+	}
+
+	public double average() {
+		double total_value = 0;
+		double total_time = 0;
+		AltosTimeValue prev = null;
+		for (AltosTimeValue tv : values) {
+			if (prev != null) {
+				total_value += (tv.value + prev.value) / 2 * (tv.time - prev.time);
+				total_time += (tv.time - prev.time);
+			}
+			prev = tv;
+		}
+		if (total_time == 0)
+			return AltosLib.MISSING;
+		return total_value / total_time;
+	}
+
+	public double average(double start_time, double end_time) {
+		double total_value = 0;
+		double total_time = 0;
+		AltosTimeValue prev = null;
+		for (AltosTimeValue tv : values) {
+			if (start_time <= tv.time && tv.time <= end_time) {
+				if (prev != null) {
+					total_value += (tv.value + prev.value) / 2 * (tv.time - start_time);
+					total_time += (tv.time - start_time);
+				}
+				start_time = tv.time;
+			}
+			prev = tv;
+		}
+		if (total_time == 0)
+			return AltosLib.MISSING;
+		return total_value / total_time;
+	}
+
+	public AltosTimeSeries integrate(AltosTimeSeries integral) {
+		double	value = 0.0;
+		double	pvalue = 0.0;
+		double 	time = 0.0;
+		boolean start = true;
+
+		for (AltosTimeValue v : values) {
+			if (start) {
+				value = 0.0;
+				start = false;
+			} else {
+				value += (pvalue + v.value) / 2.0 * (v.time - time);
+			}
+			pvalue = v.value;
+			time = v.time;
+			integral.add(time, value);
+
+		}
+		return integral;
+	}
+
+	public AltosTimeSeries differentiate(AltosTimeSeries diff) {
+		double value = 0.0;
+		double time = 0.0;
+		boolean start = true;
+
+		for (AltosTimeValue v: values) {
+			if (start) {
+				value = v.value;
+				time = v.time;
+				start = false;
+			} else {
+				double	dx = v.time - time;
+				double	dy = v.value - value;
+
+				if (dx != 0)
+					diff.add(time, dy/dx);
+
+				time = v.time;
+				value = v.value;
+			}
+		}
+		return diff;
+	}
+
+	private int find_left(int i, double dt) {
+		int j;
+		double t = values.get(i).time - dt;
+		for (j = i; j >= 0; j--)	{
+			if (values.get(j).time < t)
+				break;
+		}
+		return j + 1;
+
+	}
+
+	private int find_right(int i, double dt) {
+		int j;
+		double t = values.get(i).time + dt;
+		for (j = i; j < values.size(); j++) {
+			if (values.get(j).time > t)
+				break;
+		}
+		return j - 1;
+
+	}
+
+	private double filter_coeff(double dist, double width) {
+		double ratio = dist / (width / 2);
+
+		return Math.cos(ratio * Math.PI / 2);
+	}
+
+	public AltosTimeSeries filter(AltosTimeSeries f, double width) {
+		double	half_width = width/2;
+		for (int i = 0; i < values.size(); i++) {
+			double	center_time = values.get(i).time;
+			double	left_time = center_time - half_width;
+			double	right_time = center_time + half_width;
+			double	total_coeff = 0.0;
+			double	total_value = 0.0;
+
+			int	left = find_left(i, half_width);
+			int	right = find_right(i, half_width);
+
+			for (int j = left; j <= right; j++) {
+				double	j_time = values.get(j).time;
+
+				if (left_time <= j_time && j_time <= right_time) {
+					double	j_left = j == left ? left_time : values.get(j-1).time;
+					double	j_right = j == right ? right_time : values.get(j+1).time;
+					double	interval = (j_right - j_left) / 2.0;
+					double	coeff = filter_coeff(j_time - center_time, width) * interval;
+					double	value = values.get(j).value;
+					double	partial = value * coeff;
+
+					total_coeff += coeff;
+					total_value += partial;
+				}
+			}
+			if (total_coeff != 0.0)
+				f.add(center_time, total_value / total_coeff);
+		}
+		return f;
+	}
+
+	public AltosTimeSeries(String label, AltosUnits units) {
+		this.label = label;
+		this.units = units;
+		this.values = new ArrayList<AltosTimeValue>();
+	}
+}