2 * Copyright © 2017 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
15 package org.altusmetrum.altoslib_11;
19 public class AltosTimeSeries implements Iterable<AltosTimeValue> {
21 public AltosUnits units;
22 ArrayList<AltosTimeValue> values;
24 public void add(AltosTimeValue tv) {
28 public void add(double time, double value) {
29 add(new AltosTimeValue(time, value));
32 public AltosTimeValue get(int i) {
36 private double lerp(AltosTimeValue v0, AltosTimeValue v1, double t) {
38 if (v0.time == v1.time)
39 return (v0.value + v1.value) / 2;
41 return (v0.value * (v1.time - t) + v1.value * (t - v0.time)) / (v1.time - v0.time);
44 private int after_index(double time) {
46 int hi = values.size() - 1;
49 int mid = (lo + hi) / 2;
51 if (values.get(mid).time < time)
59 /* Compute a value for an arbitrary time */
60 public double value(double time) {
61 int after = after_index(time);
65 ret = values.get(0).value;
66 else if (after == values.size())
67 ret = values.get(after - 1).value;
69 AltosTimeValue b = values.get(after-1);
70 AltosTimeValue a = values.get(after);
71 ret = lerp(b, a, time);
76 /* Find the value just before an arbitrary time */
77 public double value_before(double time) {
78 int after = after_index(time);
81 return values.get(0).value;
82 return values.get(after-1).value;
85 /* Find the value just after an arbitrary time */
86 public double value_after(double time) {
87 int after = after_index(time);
89 if (after == values.size())
90 return values.get(after-1).value;
91 return values.get(after).value;
94 public double time_of(double value) {
95 double last = AltosLib.MISSING;
96 for (AltosTimeValue v : values) {
105 return values.size();
108 public Iterator<AltosTimeValue> iterator() {
109 return values.iterator();
112 public double max() {
113 double max = AltosLib.MISSING;
114 for (AltosTimeValue tv : values) {
115 if (max == AltosLib.MISSING || tv.value > max)
121 public double max(double start_time, double end_time) {
122 double max = AltosLib.MISSING;
123 for (AltosTimeValue tv : values) {
124 if (start_time <= tv.time && tv.time <= end_time)
125 if (max == AltosLib.MISSING || tv.value > max)
131 public double min() {
132 double min = AltosLib.MISSING;
133 for (AltosTimeValue tv : values) {
134 if (min == AltosLib.MISSING || tv.value < min)
140 public double min(double start_time, double end_time) {
141 double min = AltosLib.MISSING;
142 for (AltosTimeValue tv : values) {
143 if (start_time <= tv.time && tv.time <= end_time)
144 if (min == AltosLib.MISSING || tv.value < min)
150 public double average() {
153 for (AltosTimeValue tv : values) {
158 return AltosLib.MISSING;
159 return total / count;
162 public double average(double start_time, double end_time) {
165 for (AltosTimeValue tv : values) {
166 if (start_time <= tv.time && tv.time <= end_time) {
172 return AltosLib.MISSING;
173 return total / count;
176 public AltosTimeSeries integrate(AltosTimeSeries integral) {
180 boolean start = true;
182 for (AltosTimeValue v : values) {
187 value += (pvalue + v.value) / 2.0 * (v.time - time);
191 integral.add(time, value);
197 public AltosTimeSeries differentiate(AltosTimeSeries diff) {
200 boolean start = true;
202 for (AltosTimeValue v: values) {
208 double dx = v.time - time;
209 double dy = v.value - value;
212 diff.add(time, dy/dx);
221 private int find_left(int i, double dt) {
223 double t = values.get(i).time - dt;
224 for (j = i; j >= 0; j--) {
225 if (values.get(j).time < t)
232 private int find_right(int i, double dt) {
234 double t = values.get(i).time + dt;
235 for (j = i; j < values.size(); j++) {
236 if (values.get(j).time > t)
243 private double filter_coeff(double dist, double width) {
244 double ratio = dist / (width / 2);
246 return Math.cos(ratio * Math.PI / 2);
249 public AltosTimeSeries filter(AltosTimeSeries f, double width) {
250 double half_width = width/2;
251 for (int i = 0; i < values.size(); i++) {
252 double center_time = values.get(i).time;
253 double left_time = center_time - half_width;
254 double right_time = center_time + half_width;
255 double total_coeff = 0.0;
256 double total_value = 0.0;
258 int left = find_left(i, half_width);
259 int right = find_right(i, half_width);
261 for (int j = left; j <= right; j++) {
262 double j_time = values.get(j).time;
264 if (left_time <= j_time && j_time <= right_time) {
265 double j_left = j == left ? left_time : values.get(j-1).time;
266 double j_right = j == right ? right_time : values.get(j+1).time;
267 double interval = (j_right - j_left) / 2.0;
268 double coeff = filter_coeff(j_time - center_time, width) * interval;
270 total_coeff += coeff;
271 total_value += coeff * values.get(j).value;
274 if (total_coeff != 0.0)
275 f.add(center_time, total_value / total_coeff);
280 public AltosTimeSeries(String label, AltosUnits units) {
283 this.values = new ArrayList<AltosTimeValue>();