From 373aa32ee84b534cee0bf26006b2a3a6fc677011 Mon Sep 17 00:00:00 2001
From: oliexdev <olie.xdev@googlemail.com>
Date: Sun, 5 Jul 2020 19:34:21 +0200
Subject: [PATCH] calculate trend line like The Hacker's Diet, see issue #436

---
 .../gui/measurement/ChartMeasurementView.java | 86 +++++++++++--------
 .../gui/preferences/GraphPreferences.java     |  2 -
 .../src/main/res/layout/fragment_graph.xml    | 39 +++++----
 .../app/src/main/res/values-ar/strings.xml    |  2 -
 .../app/src/main/res/values-ca/strings.xml    |  2 -
 .../app/src/main/res/values-cs/strings.xml    |  2 -
 .../app/src/main/res/values-da/strings.xml    |  2 -
 .../app/src/main/res/values-de/strings.xml    |  2 -
 .../app/src/main/res/values-el/strings.xml    |  2 -
 .../app/src/main/res/values-es/strings.xml    |  2 -
 .../app/src/main/res/values-fr/strings.xml    |  2 -
 .../app/src/main/res/values-gl/strings.xml    |  2 -
 .../app/src/main/res/values-hr/strings.xml    |  2 -
 .../app/src/main/res/values-hu/strings.xml    |  2 -
 .../app/src/main/res/values-it/strings.xml    |  2 -
 .../app/src/main/res/values-iw/strings.xml    |  2 -
 .../app/src/main/res/values-ja/strings.xml    |  2 -
 .../app/src/main/res/values-ko/strings.xml    |  2 -
 .../app/src/main/res/values-nb/strings.xml    |  2 -
 .../app/src/main/res/values-nl/strings.xml    |  2 -
 .../app/src/main/res/values-pl/strings.xml    |  2 -
 .../src/main/res/values-pt-rBR/strings.xml    |  2 -
 .../app/src/main/res/values-ro/strings.xml    |  2 -
 .../app/src/main/res/values-ru/strings.xml    |  2 -
 .../app/src/main/res/values-sk/strings.xml    |  2 -
 .../app/src/main/res/values-sl/strings.xml    |  2 -
 .../app/src/main/res/values-sv/strings.xml    |  2 -
 .../app/src/main/res/values-tr/strings.xml    |  2 -
 .../app/src/main/res/values-uk/strings.xml    |  2 -
 .../app/src/main/res/values-vi/strings.xml    |  2 -
 .../src/main/res/values-zh-rTW/strings.xml    |  2 -
 .../app/src/main/res/values/strings.xml       |  3 +-
 .../src/main/res/xml/graph_preferences.xml    | 11 +--
 33 files changed, 73 insertions(+), 124 deletions(-)

diff --git a/android_app/app/src/main/java/com/health/openscale/gui/measurement/ChartMeasurementView.java b/android_app/app/src/main/java/com/health/openscale/gui/measurement/ChartMeasurementView.java
index 1e6d77f7..b67c38c6 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/measurement/ChartMeasurementView.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/measurement/ChartMeasurementView.java
@@ -25,7 +25,6 @@ import android.preference.PreferenceManager;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.widget.ProgressBar;
-import android.widget.Toast;
 
 import com.github.mikephil.charting.charts.LineChart;
 import com.github.mikephil.charting.components.AxisBase;
@@ -623,12 +622,9 @@ public class ChartMeasurementView extends LineChart {
             }
         }
 
+        addTrendLine(lineDataSets);
         addGoalLine(lineDataSets);
 
-        if (isInGraphKey) {
-            addRegressionLine(lineDataSets);
-        }
-
         LineData data = new LineData(lineDataSets);
         setData(data);
 
@@ -648,6 +644,7 @@ public class ChartMeasurementView extends LineChart {
         measurementLine.setColor(measurementView.getColor());
         measurementLine.setValueTextColor(ColorUtil.getTintColor(getContext()));
         measurementLine.setCircleColor(measurementView.getColor());
+        measurementLine.setCircleHoleColor(measurementView.getColor());
         measurementLine.setAxisDependency(measurementView.getSettings().isOnRightAxis() ? YAxis.AxisDependency.RIGHT : YAxis.AxisDependency.LEFT);
         measurementLine.setHighlightEnabled(true);
         measurementLine.setDrawHighlightIndicators(true);
@@ -656,6 +653,10 @@ public class ChartMeasurementView extends LineChart {
         measurementLine.setHighLightColor(Color.RED);
         measurementLine.setDrawCircles(prefs.getBoolean("pointsEnable", true));
         measurementLine.setDrawValues(prefs.getBoolean("labelsEnable", true));
+        if (prefs.getBoolean("trendLine", true)) {
+            // show only data point if trend line is enabled
+            measurementLine.enableDashedLine(0, 1, 0);
+        }
         measurementLine.setValueFormatter(new ValueFormatter() {
             @Override
             public String getPointLabel(Entry entry) {
@@ -712,51 +713,60 @@ public class ChartMeasurementView extends LineChart {
         }
     }
 
-    private void addRegressionLine(List<ILineDataSet> lineDataSets) {
-        if (prefs.getBoolean("regressionLine", false)) {
-            int regressLineOrder = 1;
+    private void addTrendLine(List<ILineDataSet> lineDataSets) {
+        if (!prefs.getBoolean("trendLine", true)) {
+            return;
+        }
 
-            try {
-                regressLineOrder = Integer.parseInt(prefs.getString("regressionLineOrder", "1"));
-            } catch (NumberFormatException e) {
-                Toast.makeText(getContext(), getContext().getString(R.string.error_value_required) + ":" + e.getMessage(), Toast.LENGTH_LONG).show();
-                prefs.edit().putString("regressionLineOrder", "1").apply();
+        List<ILineDataSet> trendlineDataSets = new ArrayList<>();
+
+        for (ILineDataSet dataSet : lineDataSets) {
+            // we need at least two data points
+            if (dataSet.getEntryCount() < 2) {
+                continue;
             }
 
-            List<ILineDataSet> regressionLineDataSets = new ArrayList<>();
+            PolynomialFitter polyFitter = new PolynomialFitter(1);
 
-            for (ILineDataSet dataSet : lineDataSets) {
-                PolynomialFitter polyFitter = new PolynomialFitter(Math.min(regressLineOrder, 100));
+            List<Entry> valuesTrendLine = new Stack<>();
+            valuesTrendLine.add(dataSet.getEntryForIndex(0));
+            polyFitter.addPoint((double) valuesTrendLine.get(0).getX(), (double) valuesTrendLine.get(0).getY());
 
-                for (int i=0; i<dataSet.getEntryCount(); i++) {
-                    Entry entry = dataSet.getEntryForIndex(i);
-                    polyFitter.addPoint((double) entry.getX(), (double) entry.getY());
-                }
+            for (int i = 1; i < dataSet.getEntryCount(); i++) {
+                Entry entry = dataSet.getEntryForIndex(i);
+                Entry trendPreviousEntry = valuesTrendLine.get(i - 1);
+                float trendYValue = (trendPreviousEntry.getY() + 0.1f * (entry.getY() - trendPreviousEntry.getY()));
+                polyFitter.addPoint((double) entry.getX(), (double) trendYValue);
+                valuesTrendLine.add(new Entry(entry.getX(), trendYValue));
+                /*Timber.d("ENTRY X " + entry.getX() + " Y " + entry.getY());
+                Timber.d("PREVIOUS X " + trendPreviousEntry.getX() + " Y " + trendPreviousEntry.getY());
+                Timber.d("TREND X " + entry.getX() + " Y " + trendYValue);*/
+            }
 
+            if (isInGraphKey) {
                 PolynomialFitter.Polynomial polynomial = polyFitter.getBestFit();
 
-                List<Entry> valuesLinearRegression = new Stack<>();
-
-                for (int i = minXValue; i < maxXValue + minXValue + 1; i++) {
+                int x_last = (int) dataSet.getEntryForIndex(dataSet.getEntryCount() - 1).getX();
+                for (int i = x_last; i < maxXValue + minXValue + 1; i++) {
                     double y_value = polynomial.getY(i);
-                    valuesLinearRegression.add(new Entry((float) i, (float) y_value));
+                    valuesTrendLine.add(new Entry((float) i, (float) y_value));
                 }
-
-                LineDataSet linearRegressionLine = new LineDataSet(valuesLinearRegression, dataSet.getLabel() + "-" + getContext().getString(R.string.label_regression_line));
-                linearRegressionLine.setLineWidth(1.5f);
-                linearRegressionLine.setColor(dataSet.getColor());
-                linearRegressionLine.setAxisDependency(dataSet.getAxisDependency());
-                linearRegressionLine.setDrawValues(false);
-                linearRegressionLine.setDrawCircles(false);
-                linearRegressionLine.setHighlightEnabled(false);
-                linearRegressionLine.enableDashedLine(10, 30, 0);
-
-                regressionLineDataSets.add(linearRegressionLine);
             }
 
-            for (ILineDataSet dataSet : regressionLineDataSets) {
-                lineDataSets.add(dataSet);
-            }
+            LineDataSet trendLine = new LineDataSet(valuesTrendLine, dataSet.getLabel() + "-" + getContext().getString(R.string.label_trend_line));
+            trendLine.setLineWidth(1.5f);
+            trendLine.setColor(dataSet.getColor());
+            trendLine.setAxisDependency(dataSet.getAxisDependency());
+            trendLine.setDrawValues(false);
+            trendLine.setDrawCircles(false);
+            trendLine.setHighlightEnabled(false);
+            //trendLine.enableDashedLine(10, 30, 0);
+
+            trendlineDataSets.add(trendLine);
+        }
+
+        for (ILineDataSet dataSet : trendlineDataSets) {
+            lineDataSets.add(dataSet);
         }
     }
 }
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/preferences/GraphPreferences.java b/android_app/app/src/main/java/com/health/openscale/gui/preferences/GraphPreferences.java
index f96d3193..96cf93be 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/preferences/GraphPreferences.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/preferences/GraphPreferences.java
@@ -25,8 +25,6 @@ import com.health.openscale.R;
 
 public class GraphPreferences extends PreferenceFragmentCompat {
 
-    private static final String PREFERENCE_KEY_REGRESSION_LINE_ORDER = "regressionLineOrder";
-
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         setPreferencesFromResource(R.xml.graph_preferences, rootKey);
diff --git a/android_app/app/src/main/res/layout/fragment_graph.xml b/android_app/app/src/main/res/layout/fragment_graph.xml
index 637f2e1c..95badc69 100644
--- a/android_app/app/src/main/res/layout/fragment_graph.xml
+++ b/android_app/app/src/main/res/layout/fragment_graph.xml
@@ -111,46 +111,49 @@
         android:id="@+id/showMenu"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:scaleType="centerInside"
-        app:fabSize="mini"
-        app:srcCompat="@drawable/ic_show"
         android:layout_below="@id/deleteMenu"
-        app:layout_anchor="@id/editMenu"
-        android:clickable="true"
-        android:visibility="gone"
-        app:layout_anchorGravity="top"
         android:layout_gravity="top|end"
-        app:pressedTranslationZ="12dp" />
+        android:clickable="true"
+        android:scaleType="centerInside"
+        android:tint="@color/widgetTextColor"
+        android:visibility="gone"
+        app:fabSize="mini"
+        app:layout_anchor="@id/editMenu"
+        app:layout_anchorGravity="top"
+        app:pressedTranslationZ="12dp"
+        app:srcCompat="@drawable/ic_show" />
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/editMenu"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        app:fabSize="mini"
-        android:scaleType="centerInside"
-        app:srcCompat="@drawable/ic_editable"
         android:layout_above="@id/deleteMenu"
-        app:backgroundTint="#99CC00"
         android:clickable="true"
+        android:scaleType="centerInside"
+        android:tint="@color/widgetTextColor"
         android:visibility="gone"
+        app:backgroundTint="#99CC00"
+        app:fabSize="mini"
         app:layout_anchor="@id/chartView"
         app:layout_anchorGravity="right|center_vertical"
-        app:pressedTranslationZ="12dp"/>
+        app:pressedTranslationZ="12dp"
+        app:srcCompat="@drawable/ic_editable" />
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/deleteMenu"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        app:fabSize="mini"
-        android:scaleType="centerInside"
+        android:layout_gravity="bottom|end"
         android:clickable="true"
+        android:scaleType="centerInside"
+        android:tint="@color/widgetTextColor"
         android:visibility="gone"
-        app:srcCompat="@drawable/ic_delete"
         app:backgroundTint="#FF4444"
+        app:fabSize="mini"
         app:layout_anchor="@id/editMenu"
         app:layout_anchorGravity="bottom"
-        android:layout_gravity="bottom|end"
-        app:pressedTranslationZ="12dp"/>
+        app:pressedTranslationZ="12dp"
+        app:srcCompat="@drawable/ic_delete" />
 
     <ProgressBar
         android:id="@+id/progressBar"
diff --git a/android_app/app/src/main/res/values-ar/strings.xml b/android_app/app/src/main/res/values-ar/strings.xml
index ce809d00..e9cd535c 100644
--- a/android_app/app/src/main/res/values-ar/strings.xml
+++ b/android_app/app/src/main/res/values-ar/strings.xml
@@ -136,8 +136,6 @@
     <string name="label_not_found">غير موجود</string>
     <string name="label_ignoreOutOfRange">تجاهل خارج نطاق البيانات</string>
     <string name="label_initial_weight">الوزن البدائي</string>
-    <string name="label_regression_line">خط الوزن الانحداري</string>
-    <string name="label_regression_line_degree">خط انحداري متعدد الحدود</string>
     <string name="label_goal_line">خط الهدف</string>
     <string name="label_help">مساعدة</string>
     <string name="label_feedback_message_enjoying">استمتعت ب openScale؟</string>
diff --git a/android_app/app/src/main/res/values-ca/strings.xml b/android_app/app/src/main/res/values-ca/strings.xml
index f96e151a..324105fe 100644
--- a/android_app/app/src/main/res/values-ca/strings.xml
+++ b/android_app/app/src/main/res/values-ca/strings.xml
@@ -119,8 +119,6 @@
     <string name="label_not_found">no s\'ha trobat</string>
     <string name="label_ignoreOutOfRange">Ignora les dades fora del rang</string>
     <string name="label_initial_weight">Pes inicial</string>
-    <string name="label_regression_line">Línia de regressió</string>
-    <string name="label_regression_line_degree">Grau del polinomi de regressió</string>
     <string name="label_goal_line">Línia de l\'objectiu</string>
     <string name="error_max_scale_users">S\'ha assolit el nombre màxim d\'usuaris simultanis de la bàscula</string>
     <string name="info_step_on_scale_for_reference">Pugeu a la bàscula amb els peus nus per a obtenir les mesures de referència</string>
diff --git a/android_app/app/src/main/res/values-cs/strings.xml b/android_app/app/src/main/res/values-cs/strings.xml
index ae3d444d..68a886c8 100644
--- a/android_app/app/src/main/res/values-cs/strings.xml
+++ b/android_app/app/src/main/res/values-cs/strings.xml
@@ -189,8 +189,6 @@
     <string name="label_enable_legend">Legenda grafu</string>
     <string name="label_enable_yaxis">Osa Y</string>
     <string name="label_enable_labels">Popisek dat</string>
-    <string name="label_regression_line">Regresivní křivka</string>
-    <string name="label_regression_line_degree">Stupeň polynomické regrese</string>
     <string name="label_goal_line">Cílová čára</string>
     <string name="info_step_on_scale_for_reference">Stoupněte na váhu naboso pro referenční měření</string>
     <string name="info_step_on_scale">Stoupněte na váhu naboso</string>
diff --git a/android_app/app/src/main/res/values-da/strings.xml b/android_app/app/src/main/res/values-da/strings.xml
index a75ea9d9..76516f3d 100644
--- a/android_app/app/src/main/res/values-da/strings.xml
+++ b/android_app/app/src/main/res/values-da/strings.xml
@@ -119,8 +119,6 @@
     <string name="label_not_found">blev ikke fundet</string>
     <string name="label_ignoreOutOfRange">Ignorér data udenfor interval</string>
     <string name="label_initial_weight">Startvægt</string>
-    <string name="label_regression_line">Vægt tilbagegang</string>
-    <string name="label_regression_line_degree">Grad af tilbagegang</string>
     <string name="label_goal_line">Mållinje</string>
     <string name="error_max_scale_users">Det maksimale antal brugere er nået</string>
     <string name="info_step_on_scale_for_reference">Træd op på vægten med bare fødder for at foretagen en referencemåling</string>
diff --git a/android_app/app/src/main/res/values-de/strings.xml b/android_app/app/src/main/res/values-de/strings.xml
index f1910c1f..d4079e93 100644
--- a/android_app/app/src/main/res/values-de/strings.xml
+++ b/android_app/app/src/main/res/values-de/strings.xml
@@ -110,8 +110,6 @@
     <string name="error_initial_weight_required">Anfangsgewicht ist erforderlich</string>
     <string name="label_bt_device_no_support">Gerät wird nicht unterstützt</string>
     <string name="label_goal_line">Ziellinie</string>
-    <string name="label_regression_line">Regressionsgerade</string>
-    <string name="label_regression_line_degree">Polynomischer Regressions-Grad</string>
     <string name="label_bluetooth_searching">Suche nach Ihrer Bluetooth Waagen</string>
     <string name="label_bone">Knochenmasse</string>
     <string name="label_bmr">Grundumsatz (BMR)</string>
diff --git a/android_app/app/src/main/res/values-el/strings.xml b/android_app/app/src/main/res/values-el/strings.xml
index 3da85a7c..91b33c89 100644
--- a/android_app/app/src/main/res/values-el/strings.xml
+++ b/android_app/app/src/main/res/values-el/strings.xml
@@ -129,8 +129,6 @@
     <string name="label_not_found">δεν βρέθηκε</string>
     <string name="label_ignoreOutOfRange">Αγνόησε δεδομένα εκτός εύρους</string>
     <string name="label_initial_weight">Αρχικό βάρος</string>
-    <string name="label_regression_line">Γραμμή παλινδρόμησης</string>
-    <string name="label_regression_line_degree">Πολυώνυμος βαθμός οπισθοδρόμησης</string>
     <string name="label_goal_line">Γραμμή στόχου</string>
     <string name="label_help">Βοήθεια</string>
     <string name="label_feedback_message_enjoying">Απολαμβάνετε το ανοιχτόςΖυγός;</string>
diff --git a/android_app/app/src/main/res/values-es/strings.xml b/android_app/app/src/main/res/values-es/strings.xml
index 0aac6364..c8871819 100644
--- a/android_app/app/src/main/res/values-es/strings.xml
+++ b/android_app/app/src/main/res/values-es/strings.xml
@@ -119,8 +119,6 @@
     <string name="label_not_found">no encontrado</string>
     <string name="label_ignoreOutOfRange">Ignorar datos fuera de límites</string>
     <string name="label_initial_weight">Peso inicial</string>
-    <string name="label_regression_line">Línea de regresión</string>
-    <string name="label_regression_line_degree">Grado de polinomio de regresión</string>
     <string name="label_goal_line">Línea del objetivo</string>
     <string name="error_max_scale_users">Máximo número de usuarios concurrentes alcanzado</string>
     <string name="info_step_on_scale_for_reference">Párese con los pies descalzos en la báscula para tomar medidas de referencia</string>
diff --git a/android_app/app/src/main/res/values-fr/strings.xml b/android_app/app/src/main/res/values-fr/strings.xml
index 4c321e96..5e93acdb 100644
--- a/android_app/app/src/main/res/values-fr/strings.xml
+++ b/android_app/app/src/main/res/values-fr/strings.xml
@@ -157,8 +157,6 @@
     <string name="label_export_dir">Dossier pour l\'exportation</string>
     <string name="label_not_found">Non trouvé</string>
     <string name="label_ignoreOutOfRange">Ignorer les valeurs hors de plage valide</string>
-    <string name="label_regression_line">Ligne de régression</string>
-    <string name="label_regression_line_degree">Degré du polynôme pour la ligne</string>
     <string name="label_goal_line">Ligne pour l\'objectif</string>
     <string name="label_feedback_message_enjoying">Êtes-vous satisfait d\'openScale ?</string>
     <string name="label_feedback_message_rate_app">Laisser une évaluation sur Google Play ou GitHub ?</string>
diff --git a/android_app/app/src/main/res/values-gl/strings.xml b/android_app/app/src/main/res/values-gl/strings.xml
index e096a8f0..c8435469 100644
--- a/android_app/app/src/main/res/values-gl/strings.xml
+++ b/android_app/app/src/main/res/values-gl/strings.xml
@@ -126,8 +126,6 @@
     <string name="label_not_found">non atopado</string>
     <string name="label_ignoreOutOfRange">Ignorar datos fóra de rango</string>
     <string name="label_initial_weight">Peso inicial</string>
-    <string name="label_regression_line">Liña de tendencia de peso</string>
-    <string name="label_regression_line_degree">Grao do polinomio de regresión (tendencia)</string>
     <string name="label_goal_line">Liña do obxectivo</string>
     <string name="label_help">Axuda</string>
     <string name="label_feedback_message_enjoying">Gústache openScale?</string>
diff --git a/android_app/app/src/main/res/values-hr/strings.xml b/android_app/app/src/main/res/values-hr/strings.xml
index 450674c2..51ddfd65 100644
--- a/android_app/app/src/main/res/values-hr/strings.xml
+++ b/android_app/app/src/main/res/values-hr/strings.xml
@@ -131,8 +131,6 @@
     <string name="label_not_found">nije pronađeno</string>
     <string name="label_ignoreOutOfRange">Zanemari podatke izvan granica</string>
     <string name="label_initial_weight">Početna težina</string>
-    <string name="label_regression_line">Linija regresije</string>
-    <string name="label_regression_line_degree">Polinom regresije</string>
     <string name="label_goal_line">Ciljana linija</string>
     <string name="label_help">Pomoć</string>
     <string name="label_feedback_message_enjoying">Sviđa ti se openScale\?</string>
diff --git a/android_app/app/src/main/res/values-hu/strings.xml b/android_app/app/src/main/res/values-hu/strings.xml
index 12fbf5ee..25f762ea 100644
--- a/android_app/app/src/main/res/values-hu/strings.xml
+++ b/android_app/app/src/main/res/values-hu/strings.xml
@@ -125,8 +125,6 @@
     <string name="info_on_date">be</string>
     <string name="label_ignoreOutOfRange">Tartományon kívüli adat elhagyása</string>
     <string name="label_initial_weight">Kezdő súly</string>
-    <string name="label_regression_line">Regressziós egyenes</string>
-    <string name="label_regression_line_degree">Polinom regresszió foka</string>
     <string name="label_goal_line">Cél vonal</string>
     <string name="label_help">Segítség</string>
     <string name="label_feedback_message_enjoying">Élvezi az openScale-t\?</string>
diff --git a/android_app/app/src/main/res/values-it/strings.xml b/android_app/app/src/main/res/values-it/strings.xml
index 0c543010..acba3a2a 100644
--- a/android_app/app/src/main/res/values-it/strings.xml
+++ b/android_app/app/src/main/res/values-it/strings.xml
@@ -129,8 +129,6 @@
     <string name="label_not_found">non trovato</string>
     <string name="label_ignoreOutOfRange">Ignorare i dati fuori intervallo</string>
     <string name="label_initial_weight">Peso iniziale</string>
-    <string name="label_regression_line">Retta di regressione</string>
-    <string name="label_regression_line_degree">Grado di regressione polinomiale</string>
     <string name="label_goal_line">Linea obiettivo</string>
     <string name="label_help">Aiuto</string>
     <string name="label_feedback_message_enjoying">Ti piace openScale?</string>
diff --git a/android_app/app/src/main/res/values-iw/strings.xml b/android_app/app/src/main/res/values-iw/strings.xml
index 8d5832e2..ac9650c6 100644
--- a/android_app/app/src/main/res/values-iw/strings.xml
+++ b/android_app/app/src/main/res/values-iw/strings.xml
@@ -131,8 +131,6 @@
     <string name="label_not_found">לא נמצא</string>
     <string name="label_ignoreOutOfRange">התעלמות מנתונים מחוץ לטווח</string>
     <string name="label_initial_weight">משקל ראשוני</string>
-    <string name="label_regression_line">קו נסיגתי</string>
-    <string name="label_regression_line_degree">רמה פולינומית של נסיגה</string>
     <string name="label_goal_line">קו יעד</string>
     <string name="label_help">עזרה</string>
     <string name="label_feedback_message_enjoying">השימוש ב־openScale מטיב עמך\?</string>
diff --git a/android_app/app/src/main/res/values-ja/strings.xml b/android_app/app/src/main/res/values-ja/strings.xml
index 1548f3d1..074901ed 100644
--- a/android_app/app/src/main/res/values-ja/strings.xml
+++ b/android_app/app/src/main/res/values-ja/strings.xml
@@ -168,8 +168,6 @@
     <string name="label_category_measurement_database">測定データベース</string>
     <string name="label_export_dir">エクスポートディレクトリー</string>
     <string name="label_not_found">見つかりません</string>
-    <string name="label_regression_line">回帰線</string>
-    <string name="label_regression_line_degree">回帰多項式次数</string>
     <string name="label_goal_line">目標線</string>
     <string name="error_max_scale_users">最大同時測定のユーザー数に達しました</string>
     <string name="info_step_on_scale">裸足で体重計に載ってください</string>
diff --git a/android_app/app/src/main/res/values-ko/strings.xml b/android_app/app/src/main/res/values-ko/strings.xml
index b8d51a25..1f6efd0a 100644
--- a/android_app/app/src/main/res/values-ko/strings.xml
+++ b/android_app/app/src/main/res/values-ko/strings.xml
@@ -128,8 +128,6 @@
     <string name="label_not_found">발견되지 않음</string>
     <string name="label_ignoreOutOfRange">범위를 벗어난 데이터 무시</string>
     <string name="label_initial_weight">초기 무게</string>
-    <string name="label_regression_line">회귀 무게 선</string>
-    <string name="label_regression_line_degree">회귀 다항식 차수</string>
     <string name="label_goal_line">목표선</string>
     <string name="label_help">도움말</string>
     <string name="label_feedback_message_enjoying">openScale을 잘 사용하고 계신가요\?</string>
diff --git a/android_app/app/src/main/res/values-nb/strings.xml b/android_app/app/src/main/res/values-nb/strings.xml
index 4bd96b6f..19a56acb 100644
--- a/android_app/app/src/main/res/values-nb/strings.xml
+++ b/android_app/app/src/main/res/values-nb/strings.xml
@@ -130,8 +130,6 @@
     <string name="label_not_found">ikke funnet</string>
     <string name="label_ignoreOutOfRange">Ignorer data utenfor rekkevidde</string>
     <string name="label_initial_weight">Startvekt</string>
-    <string name="label_regression_line">Regresjonslinje</string>
-    <string name="label_regression_line_degree">Regresjonspolynom-grunntall</string>
     <string name="label_goal_line">Mållinje</string>
     <string name="label_help">Hjelp</string>
     <string name="label_feedback_message_enjoying">Setter du pris på openScale?</string>
diff --git a/android_app/app/src/main/res/values-nl/strings.xml b/android_app/app/src/main/res/values-nl/strings.xml
index f0578bd3..f4f47de6 100644
--- a/android_app/app/src/main/res/values-nl/strings.xml
+++ b/android_app/app/src/main/res/values-nl/strings.xml
@@ -130,8 +130,6 @@
     <string name="label_not_found">niet gevonden</string>
     <string name="label_ignoreOutOfRange">Gegevens buiten bereik negeren</string>
     <string name="label_initial_weight">Startgewicht</string>
-    <string name="label_regression_line">Regressiegewichtslijn</string>
-    <string name="label_regression_line_degree">Regressiepolynoomgraad</string>
     <string name="label_goal_line">Doellijn</string>
     <string name="label_help">Hulp</string>
     <string name="label_feedback_message_enjoying">Gebruik je openScale graag\?</string>
diff --git a/android_app/app/src/main/res/values-pl/strings.xml b/android_app/app/src/main/res/values-pl/strings.xml
index 09cd28e5..97d1e3cf 100644
--- a/android_app/app/src/main/res/values-pl/strings.xml
+++ b/android_app/app/src/main/res/values-pl/strings.xml
@@ -130,8 +130,6 @@
     <string name="label_not_found">nie znaleziono</string>
     <string name="label_ignoreOutOfRange">Ignoruj dane spoza zakresu</string>
     <string name="label_initial_weight">Waga początkowa</string>
-    <string name="label_regression_line">Krzywa aproksymacji</string>
-    <string name="label_regression_line_degree">Stopień wielomianu aproksymacji</string>
     <string name="label_goal_line">Linia celu</string>
     <string name="label_help">Pomoc</string>
     <string name="label_feedback_message_enjoying">Podoba Ci się openScale?</string>
diff --git a/android_app/app/src/main/res/values-pt-rBR/strings.xml b/android_app/app/src/main/res/values-pt-rBR/strings.xml
index 1845c4a2..49ee21fd 100644
--- a/android_app/app/src/main/res/values-pt-rBR/strings.xml
+++ b/android_app/app/src/main/res/values-pt-rBR/strings.xml
@@ -83,8 +83,6 @@
     <string name="label_no">Não</string>
     <string name="label_ok">OK</string>
     <string name="label_not_found">não encontrado</string>
-    <string name="label_regression_line">Linha de tendência de peso</string>
-    <string name="label_regression_line_degree">Grau de regressão polinomial (tendência)</string>
     <string name="label_reminder">Lembrete</string>
     <string name="label_reminder_notify_text">Título da notificação</string>
     <string name="label_reminder_time">Hora</string>
diff --git a/android_app/app/src/main/res/values-ro/strings.xml b/android_app/app/src/main/res/values-ro/strings.xml
index 2d50ca1d..9b745ef4 100644
--- a/android_app/app/src/main/res/values-ro/strings.xml
+++ b/android_app/app/src/main/res/values-ro/strings.xml
@@ -140,8 +140,6 @@
     <string name="label_not_found">negăsit</string>
     <string name="label_ignoreOutOfRange">Ignorare a valorilor invalide</string>
     <string name="label_initial_weight">Greutate inițială</string>
-    <string name="label_regression_line">Linie de regresie</string>
-    <string name="label_regression_line_degree">Gradul polinomului</string>
     <string name="label_goal_line">Linie pentru obiectiv</string>
     <string name="label_help">Ajutor</string>
 
diff --git a/android_app/app/src/main/res/values-ru/strings.xml b/android_app/app/src/main/res/values-ru/strings.xml
index 75f55d31..eededb7f 100644
--- a/android_app/app/src/main/res/values-ru/strings.xml
+++ b/android_app/app/src/main/res/values-ru/strings.xml
@@ -172,8 +172,6 @@
     <string name="label_enable_labels">Метка данных</string>
     <string name="default_value_reminder_notify_text">Пора взвеситься</string>
     <string name="info_on_date">в день</string>
-    <string name="label_regression_line">График снижения веса</string>
-    <string name="label_regression_line_degree">Степень полиномиальной регрессии</string>
     <string name="label_feedback_message_rate_app">Поставить оценку на Google Play или GitHub\?</string>
     <string name="trisa_scale_not_paired">Эти весы не были подключены!
 \n
diff --git a/android_app/app/src/main/res/values-sk/strings.xml b/android_app/app/src/main/res/values-sk/strings.xml
index 79926ec3..c211a9b2 100644
--- a/android_app/app/src/main/res/values-sk/strings.xml
+++ b/android_app/app/src/main/res/values-sk/strings.xml
@@ -113,8 +113,6 @@
     <string name="label_not_found">nenájdený</string>
     <string name="label_ignoreOutOfRange">Ignorovať údaje mimo rozsah</string>
     <string name="label_initial_weight">Počiatočná hmotnosť</string>
-    <string name="label_regression_line">Vývoj úbytku</string>
-    <string name="label_regression_line_degree">Stupeň polynomiálnej regresie</string>
     <string name="label_goal_line">Cieľová línia</string>
     <string name="error_max_scale_users">Dosiahli ste maximálny počet používateľov</string>
     <string name="info_step_on_scale_for_reference">Prosím, postavte sa na váhu pre referenčné meranie</string>
diff --git a/android_app/app/src/main/res/values-sl/strings.xml b/android_app/app/src/main/res/values-sl/strings.xml
index 26af73c0..c2af9431 100644
--- a/android_app/app/src/main/res/values-sl/strings.xml
+++ b/android_app/app/src/main/res/values-sl/strings.xml
@@ -152,8 +152,6 @@
     <string name="label_not_found">nič ni bilo najdeno</string>
     <string name="label_ignoreOutOfRange">Ignoriraj vrednosti zunaj meje</string>
     <string name="label_initial_weight">Začetna teža</string>
-    <string name="label_regression_line">Regresijska krivulja teže</string>
-    <string name="label_regression_line_degree">Regresija polinomske stopnje</string>
     <string name="label_goal_line">Ciljna krivulja</string>
     <string name="label_help">Pomoč</string>
 
diff --git a/android_app/app/src/main/res/values-sv/strings.xml b/android_app/app/src/main/res/values-sv/strings.xml
index ac421a35..0a037f2e 100644
--- a/android_app/app/src/main/res/values-sv/strings.xml
+++ b/android_app/app/src/main/res/values-sv/strings.xml
@@ -119,8 +119,6 @@
     <string name="label_not_found">hittades inte</string>
     <string name="label_ignoreOutOfRange">Ignorera data utanför intervall</string>
     <string name="label_initial_weight">Startvikt</string>
-    <string name="label_regression_line">Regressionslinje</string>
-    <string name="label_regression_line_degree">Regressions-polynom-gradtal</string>
     <string name="label_goal_line">Mållinje</string>
     <string name="error_max_scale_users">Max antal samtidiga våganvändare nått</string>
     <string name="info_step_on_scale_for_reference">Kliv upp barfota på vågen för referensmätningar</string>
diff --git a/android_app/app/src/main/res/values-tr/strings.xml b/android_app/app/src/main/res/values-tr/strings.xml
index 53a86700..0e75037f 100644
--- a/android_app/app/src/main/res/values-tr/strings.xml
+++ b/android_app/app/src/main/res/values-tr/strings.xml
@@ -119,8 +119,6 @@
     <string name="label_not_found">Bulunamadı</string>
     <string name="label_ignoreOutOfRange">Aralığın dışındaki verileri yoksay</string>
     <string name="label_initial_weight">Başlangıç ağırlığı</string>
-    <string name="label_regression_line">Ağırlık çizgisinde gerileme</string>
-    <string name="label_regression_line_degree">polinom derecesinde gerileme</string>
     <string name="label_goal_line">Hedef çizgisi</string>
     <string name="error_max_scale_users">Ençok eşzamanlı tartı kullanıcı sayısına ulaştı</string>
     <string name="info_step_on_scale_for_reference">Referans ölçümleri için lütfen tartıya çıplak ayakla çıkın</string>
diff --git a/android_app/app/src/main/res/values-uk/strings.xml b/android_app/app/src/main/res/values-uk/strings.xml
index e86c6f08..0ee179c1 100644
--- a/android_app/app/src/main/res/values-uk/strings.xml
+++ b/android_app/app/src/main/res/values-uk/strings.xml
@@ -135,8 +135,6 @@
     <string name="label_not_found">не знайдено</string>
     <string name="label_ignoreOutOfRange">Ігнорувати дані за межами діапазону</string>
     <string name="label_initial_weight">Початкова вага</string>
-    <string name="label_regression_line">Графік зниження</string>
-    <string name="label_regression_line_degree">Ступінь поліномінальної регресії</string>
     <string name="label_goal_line">Лінія мети</string>
     <string name="label_help">Допомога</string>
     <string name="label_feedback_message_enjoying">До вподоби openScale\?</string>
diff --git a/android_app/app/src/main/res/values-vi/strings.xml b/android_app/app/src/main/res/values-vi/strings.xml
index a7d72293..42fd1314 100644
--- a/android_app/app/src/main/res/values-vi/strings.xml
+++ b/android_app/app/src/main/res/values-vi/strings.xml
@@ -149,8 +149,6 @@
     <string name="label_not_found">không tìm thấy</string>
     <string name="label_ignoreOutOfRange">Bỏ qua dữ liệu ngoài phạm vi</string>
     <string name="label_initial_weight">Trọng lượng ban đầu</string>
-    <string name="label_regression_line">Đường trọng lượng hồi quy</string>
-    <string name="label_regression_line_degree">Mức độ hồi quy đa thức</string>
     <string name="label_goal_line">Đường thẳng mục tiêu</string>
     <string name="label_help">Trợ giúp</string>
 
diff --git a/android_app/app/src/main/res/values-zh-rTW/strings.xml b/android_app/app/src/main/res/values-zh-rTW/strings.xml
index 9a1e4269..a1e007da 100644
--- a/android_app/app/src/main/res/values-zh-rTW/strings.xml
+++ b/android_app/app/src/main/res/values-zh-rTW/strings.xml
@@ -128,8 +128,6 @@
     <string name="label_not_found">尋找不到</string>
     <string name="label_ignoreOutOfRange">忽略超出範圍的資料</string>
     <string name="label_initial_weight">初始體重</string>
-    <string name="label_regression_line">體重回歸線</string>
-    <string name="label_regression_line_degree">回歸線曲度</string>
     <string name="label_goal_line">目標線</string>
     <string name="label_help">協助</string>
     <string name="label_feedback_message_enjoying">openScale 使用愉快嗎?</string>
diff --git a/android_app/app/src/main/res/values/strings.xml b/android_app/app/src/main/res/values/strings.xml
index 443113a3..770e50e9 100644
--- a/android_app/app/src/main/res/values/strings.xml
+++ b/android_app/app/src/main/res/values/strings.xml
@@ -149,8 +149,7 @@
     <string name="label_not_found">not found</string>
     <string name="label_ignoreOutOfRange">Ignore out of range data</string>
     <string name="label_initial_weight">Initial weight</string>
-    <string name="label_regression_line">Regression line</string>
-    <string name="label_regression_line_degree">Regression polynomial degree</string>
+    <string name="label_trend_line">Trend line</string>
     <string name="label_goal_line">Goal line</string>
     <string name="label_help">Help</string>
     <string name="label_feedback_message_enjoying">Enjoying openScale?</string>
diff --git a/android_app/app/src/main/res/xml/graph_preferences.xml b/android_app/app/src/main/res/xml/graph_preferences.xml
index 5f2b98c1..ff198aa0 100644
--- a/android_app/app/src/main/res/xml/graph_preferences.xml
+++ b/android_app/app/src/main/res/xml/graph_preferences.xml
@@ -25,14 +25,9 @@
         android:summaryOn="@string/info_is_visible"
         android:title="@string/label_goal_line" />
     <CheckBoxPreference
-        android:defaultValue="false"
-        android:key="regressionLine"
+        android:defaultValue="true"
+        android:key="trendLine"
         android:summaryOff="@string/info_is_not_visible"
         android:summaryOn="@string/info_is_visible"
-        android:title="@string/label_regression_line" />
-    <EditTextPreference
-        android:defaultValue="1"
-        android:dependency="regressionLine"
-        android:key="regressionLineOrder"
-        android:title="@string/label_regression_line_degree" />
+        android:title="@string/label_trend_line" />
 </PreferenceScreen>