From 98dc29a7a964f8d653b73989c6751695d168844c Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 2 Oct 2017 19:33:37 -0700 Subject: altoslib: Add user-selectable filter width for data smoothing Also switch smoothing window to Kaiser and change default accel filter width to 1 second instead of 4 seconds. Now users can play with the filter and see what it does. Signed-off-by: Keith Packard --- altoslib/AltosFlightSeries.java | 90 +++++++++++++++++++++++++++++------------ altoslib/AltosTimeSeries.java | 42 +++++++++++++++++-- altoslib/Makefile.am | 1 + 3 files changed, 105 insertions(+), 28 deletions(-) (limited to 'altoslib') diff --git a/altoslib/AltosFlightSeries.java b/altoslib/AltosFlightSeries.java index ab7943b3..02bf64ff 100644 --- a/altoslib/AltosFlightSeries.java +++ b/altoslib/AltosFlightSeries.java @@ -21,7 +21,7 @@ public class AltosFlightSeries extends AltosDataListener { public ArrayList series = new ArrayList(); public double speed_filter_width = 4.0; - public double accel_filter_width = 4.0; + public double accel_filter_width = 1.0; public int[] indices() { int[] indices = new int[series.size()]; @@ -160,6 +160,7 @@ public class AltosFlightSeries extends AltosDataListener { } public AltosTimeSeries accel_series; + public boolean accel_computed; public static final String accel_name = "Accel"; @@ -174,17 +175,44 @@ public class AltosFlightSeries extends AltosDataListener { accel_series = add_series(accel_name, AltosConvert.accel); accel_series.add(time(), acceleration); + accel_computed = false; } - private void compute_accel() { - if (accel_series != null) - return; + private AltosTimeSeries compute_accel() { + AltosTimeSeries new_accel_series = null; if (speed_series != null) { - AltosTimeSeries temp_series = make_series(speed_name, AltosConvert.speed); - speed_series.filter(temp_series, accel_filter_width); - accel_series = add_series(accel_name, AltosConvert.accel); - temp_series.differentiate(accel_series); + AltosTimeSeries temp_series; + if (accel_filter_width > 0) { + temp_series = make_series(speed_name, AltosConvert.speed); + speed_series.filter(temp_series, accel_filter_width); + } else + temp_series = speed_series; + + new_accel_series = make_series(accel_name, AltosConvert.accel); + temp_series.differentiate(new_accel_series); + } + return new_accel_series; + } + + public void set_filter(double speed_filter, double accel_filter) { + this.speed_filter_width = speed_filter; + this.accel_filter_width = accel_filter; + + AltosTimeSeries new_speed_series = compute_speed(); + + if (new_speed_series != null) { + speed_series.erase_values(); + for (AltosTimeValue tv : new_speed_series) + speed_series.add(tv); + } + if (accel_computed) { + AltosTimeSeries new_accel_series = compute_accel(); + if (new_accel_series != null) { + accel_series.erase_values(); + for (AltosTimeValue tv : new_accel_series) + accel_series.add(tv); + } } } @@ -268,21 +296,24 @@ public class AltosFlightSeries extends AltosDataListener { public static final String speed_name = "Speed"; - private void compute_speed() { - if (speed_series != null) - return; - + private AltosTimeSeries compute_speed() { + AltosTimeSeries new_speed_series = null; AltosTimeSeries alt_speed_series = null; AltosTimeSeries accel_speed_series = null; if (altitude_series != null) { - AltosTimeSeries temp_series = make_series(altitude_name, AltosConvert.height); - altitude_series.filter(temp_series, speed_filter_width); + AltosTimeSeries temp_series; + + if (speed_filter_width > 0) { + temp_series = make_series(speed_name, AltosConvert.height); + altitude_series.filter(temp_series, speed_filter_width); + } else + temp_series = altitude_series; alt_speed_series = make_series(speed_name, AltosConvert.speed); temp_series.differentiate(alt_speed_series); } - if (accel_series != null) { + if (accel_series != null && !accel_computed) { if (orient_series != null) { vert_accel_series = add_series(vert_accel_name, AltosConvert.accel); @@ -318,26 +349,25 @@ public class AltosFlightSeries extends AltosDataListener { } } if (apogee_time == AltosLib.MISSING) { - speed_series = alt_speed_series; + new_speed_series = alt_speed_series; } else { - speed_series = make_series(speed_name, AltosConvert.speed); + new_speed_series = make_series(speed_name, AltosConvert.speed); for (AltosTimeValue d : accel_speed_series) { if (d.time <= apogee_time) - speed_series.add(d); + new_speed_series.add(d); } for (AltosTimeValue d : alt_speed_series) { if (d.time > apogee_time) - speed_series.add(d); + new_speed_series.add(d); } } } else if (alt_speed_series != null) { - speed_series = alt_speed_series; + new_speed_series = alt_speed_series; } else if (accel_speed_series != null) { - speed_series = accel_speed_series; + new_speed_series = accel_speed_series; } - if (speed_series != null) - add_series(speed_series); + return new_speed_series; } public AltosTimeSeries orient_series; @@ -690,8 +720,18 @@ public class AltosFlightSeries extends AltosDataListener { public void finish() { compute_orient(); - compute_speed(); - compute_accel(); + if (speed_series == null) { + speed_series = compute_speed(); + if (speed_series != null) + add_series(speed_series); + } + if (accel_series == null) { + accel_series = compute_accel(); + if (accel_series != null) { + add_series(accel_series); + accel_computed = true; + } + } compute_height(); } diff --git a/altoslib/AltosTimeSeries.java b/altoslib/AltosTimeSeries.java index 9f3b4d80..7208c176 100644 --- a/altoslib/AltosTimeSeries.java +++ b/altoslib/AltosTimeSeries.java @@ -20,15 +20,30 @@ public class AltosTimeSeries implements Iterable, Comparable values; + boolean data_changed; public int compareTo(AltosTimeSeries other) { return label.compareTo(other.label); } public void add(AltosTimeValue tv) { + data_changed = true; values.add(tv); } + public void erase_values() { + data_changed = true; + this.values = new ArrayList(); + } + + public void clear_changed() { + data_changed = false; + } + +// public boolean changed() { +// return data_changed; +// } + public void add(double time, double value) { add(new AltosTimeValue(time, value)); } @@ -264,14 +279,35 @@ public class AltosTimeSeries implements Iterable, Comparable 0); + return s; + } + + private static double kaiser(double n, double m, double beta) { + double alpha = m / 2; + double t = (n - alpha) / alpha; + + if (t > 1) + t = 1; + double k = i0 (beta * Math.sqrt (1 - t*t)) / i0(beta); + return k; + } + + private double filter_coeff(double dist, double width) { + return kaiser(dist + width/2.0, width, 2 * Math.PI); } public AltosTimeSeries filter(AltosTimeSeries f, double width) { + double half_width = width/2; + int half_point = values.size() / 2; for (int i = 0; i < values.size(); i++) { double center_time = values.get(i).time; double left_time = center_time - half_width; diff --git a/altoslib/Makefile.am b/altoslib/Makefile.am index 08af9496..2a1cb8e4 100644 --- a/altoslib/Makefile.am +++ b/altoslib/Makefile.am @@ -55,6 +55,7 @@ altoslib_JAVA = \ AltosEepromList.java \ AltosEepromLog.java \ AltosFile.java \ + AltosFilterListener.java \ AltosFlash.java \ AltosFlashListener.java \ AltosDataListener.java \ -- cgit v1.2.3