--- /dev/null
+/*
+ * 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>();
+ }
+}
projects / fw / altos / blobdiff