Produced some unit tests for the seizure detection algorithm

app/build.gradle

@@ -20,6 +20,9 @@ android {
 
     testOptions {
         unitTests.returnDefaultValues = true
+        unitTests {
+            includeAndroidResources = true
+        }
     }
 }
 
@@ -42,6 +45,7 @@ dependencies {
     implementation 'com.github.wendykierp:JTransforms:3.0'
     implementation 'com.google.android.gms:play-services-location:10.0.0'
     //implementation 'com.github.RohitSurwase.UCE-Handler:uce_handler:1.3'
+    testImplementation 'org.robolectric:robolectric:4.3'
 
 }
 

app/src/main/java/uk/org/openseizuredetector/SdAnalyser.java

@@ -43,7 +43,7 @@ public class SdAnalyser {
     private double mWarnTime;
     private double mAlarmTime;
     private double mAlarmThresh;
-    private double mAlarmRatioThresh;
+    double mAlarmRatioThresh;
     private double mFreqRes;
     private int mAlarmCount;
     private double mFreqCutoff;
@@ -79,13 +79,10 @@ public class SdAnalyser {
     }
 
     /**
-     * doAnalysis() - analyse the data if the accelerometer data array mAccData
+     * getSpecPower(rawData):  Calculate the average bin power in the spectrum of rawData
-     * and populate the output data structure mSdData
+     * between 0 and freqCutoff Hz, excluding the DC component
      */
-    void calculateSpectralPowers(double[] rawData) {
+    double getSpecPower(double[] rawData) {
-        // Set the frequency bounds for the analysis in fft output bin numbers.
-        int nMin = freq2fftBin(mAlarmFreqMin);
-        int nMax = freq2fftBin(mAlarmFreqMax);
         int nFreqCutoff = freq2fftBin(mFreqCutoff);
 
         DoubleFFT_1D fftDo = new DoubleFFT_1D(mNSamp);
@@ -104,7 +101,24 @@ public class SdAnalyser {
                 fft[2 * i + 1] = 0.;
             }
         }
-        specPower = specPower / (mNSamp / 2);
+        specPower = specPower / mNSamp / 2;
+        return(specPower);
+    }
+
+    /**
+     * getRoiPower(rawData):  Calculate the average bin power in the spectrum of rawData
+     * between alarmFreqMin and alarmFreqMax Hz.
+     */
+    double getRoiPower(double[] rawData) {
+        // Set the frequency bounds for the analysis in fft output bin numbers.
+        int nMin = freq2fftBin(mAlarmFreqMin);
+        int nMax = freq2fftBin(mAlarmFreqMax);
+        int nFreqCutoff = freq2fftBin(mFreqCutoff);
+
+        DoubleFFT_1D fftDo = new DoubleFFT_1D(mNSamp);
+        double[] fft = new double[mNSamp * 2];
+        System.arraycopy(rawData, 0, fft, 0, mNSamp);
+        fftDo.realForward(fft);
 
         // Calculate the Region of Interest power and power ratio.
         double roiPower = 0;
@@ -112,10 +126,49 @@ public class SdAnalyser {
             roiPower = roiPower + getMagnitude(fft, i);
         }
         roiPower = roiPower / (nMax - nMin);
-        double roiRatio = 10 * roiPower / specPower;
+        return(roiPower);
-
     }
 
+    /**
+     * getSpectrumRatio(rawData) - return the ratio of the ROI power to the whole spectrum power.
+     * @param rawData
+     * @return
+     */
+    double getSpectrumRatio(double rawData[]) {
+        double specPower;
+        double roiPower;
+        double specRatio;
+
+        specPower = getSpecPower(rawData);
+        roiPower = getRoiPower(rawData);
+
+        if (specPower > mAlarmThresh) {
+            specRatio = 10.0 * roiPower / specPower;
+        } else {
+            specRatio = 0.0;
+        }
+        return(specRatio);
+    }
+
+    /**
+     * getAlarmState(rawData) - determines the alarm state associated with the snapshot of raw
+     * acceleration data rawData[]
+     * @return the alarm state (0=ok, 1 = alarm)
+     */
+    int getAlarmState(double rawData[]) {
+        int alarmState;
+
+        double alarmRatio = getSpectrumRatio(rawData);
+
+        if (alarmRatio <= mAlarmRatioThresh) {
+            alarmState = 0;
+        } else {
+            alarmState = 1;
+        }
+        return(alarmState);
+    }
+
+
     /**
      * Calculate the magnitude of entry i in the fft array fft
      *
@@ -129,67 +182,34 @@ public class SdAnalyser {
         return mag;
     }
 
-    // Force the data stored in this datasource to update in line with the JSON string encoded data provided.
+    double[] getAccelDataFromJSON(String jsonStr) {
-    // Used by webServer to update the GarminDatasource.
-    // Returns a message string that is passed back to the watch.
-    public String updateFromJSON(String jsonStr) {
         String retVal = "undefined";
-        Log.v(TAG,"updateFromJSON - "+jsonStr);
+        double[] rawData = new double[mNSamp];
+        Log.v(TAG,"getAccelDataFromJSON - "+jsonStr);
 
         try {
-            JSONObject mainObject = new JSONObject(jsonStr);
+            JSONObject mainObject = null;
-            //JSONObject dataObject = mainObject.getJSONObject("dataObj");
+            mainObject = new JSONObject(jsonStr);
             JSONObject dataObject = mainObject;
             String dataTypeStr = dataObject.getString("dataType");
-            Log.v(TAG,"updateFromJSON - dataType="+dataTypeStr);
+            Log.v(TAG,"getAccelDataFromJSON - dataType="+dataTypeStr);
             if (dataTypeStr.equals("raw")) {
-                Log.v(TAG,"updateFromJSON - processing raw data");
+                Log.v(TAG, "getAccelDataFromJSON - processing raw data");
-                try {
-                    mSdData.mHR = dataObject.getDouble("HR");
-                } catch (JSONException e) {
-                    // if we get 'null' HR (For example if the heart rate is not working)
-                    mSdData.mHR = -1;
-                }
-                try {
-                    mMute = dataObject.getInt("Mute");
-                } catch (JSONException e) {
-                    // if we get 'null' HR (For example if the heart rate is not working)
-                    mMute = 0;
-                }
                 JSONArray accelVals = dataObject.getJSONArray("data");
                 Log.v(TAG, "Received " + accelVals.length() + " acceleration values");
                 int i;
                 for (i = 0; i < accelVals.length(); i++) {
-                    mSdData.rawData[i] = accelVals.getInt(i);
+                    rawData[i] = accelVals.getInt(i);
                 }
-                mSdData.mNsamp = accelVals.length();
-                //mNSamp = accelVals.length();
-                mWatchAppRunningCheck = true;
-                doAnalysis();
-                if (mSdData.haveSettings == false) {
-                    retVal = "sendSettings";
-                } else {
-                    retVal = "OK";
-                }
-            } else if (dataTypeStr.equals("settings")){
-                Log.v(TAG,"updateFromJSON - processing settings");
-                mSamplePeriod = (short)dataObject.getInt("analysisPeriod");
-                mSampleFreq = (short)dataObject.getInt("sampleFreq");
-                mSdData.batteryPc = (short)dataObject.getInt("battery");
-                Log.v(TAG,"updateFromJSON - mSamplePeriod="+mSamplePeriod+" mSampleFreq="+mSampleFreq);
-                mSdData.haveSettings = true;
-                mSdData.mSampleFreq = mSampleFreq;
-                mWatchAppRunningCheck = true;
-                retVal = "OK";
             } else {
-                Log.e(TAG,"updateFromJSON - unrecognised dataType "+dataTypeStr);
+                Log.e(TAG,"getAccelDataFromJSON - unrecognised dataType "+dataTypeStr);
                 retVal = "ERROR";
             }
         } catch (Exception e) {
-            Log.e(TAG,"updateFromJSON - Error Parsing JSON String - "+e.toString());
+            Log.e(TAG,"getAccelDataFromJSON - Error Parsing JSON String - "+e.toString());
             e.printStackTrace();
             retVal = "ERROR";
         }
-        return(retVal);
+        return(rawData);
     }
 }

app/src/test/java/uk/org/openseizuredetector/SdAnalyserTest.java

@@ -3,14 +3,17 @@ package uk.org.openseizuredetector;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
 
 import static org.junit.Assert.*;
 
+@RunWith(RobolectricTestRunner.class)
 public class SdAnalyserTest {
     public SdAnalyser sda;
 
-    public String alarmJSON = "{ dataType: 'raw', " +
+    public String alarmJSON = "{ 'dataType': 'raw', " +
-            "data: [" +
+            "'data': [" +
             "1644, 1316, 1144, 1332, 1716, 1716, 1392, 1148, 1276, 1660, " +
             "1716, 1496, 1196, 1232, 1572, 1684, 1552, 1236, 1228, 1528, " +
             "1648, 1572, 1268, 1208, 1492, 1680, 1596, 1272, 1192, 1424, " +
@@ -24,13 +27,13 @@ public class SdAnalyserTest {
             "1188, 1360, 1680, 1724, 1424, 1192, 1224, 1556, 1744, 1588, " +
             "1260, 1220, 1472, 1692, 1608, 1328, 1192, 1412, 1668, 1656, " +
             "1356, 1216, 1304, 1636, 1712], " +
-            "HR:54, " +
+            "'HR':54, " +
-            "Mute:0 " +
+            "'Mute':0 " +
             "}";
 
     private String okJSON = "{ " +
-            "dataType: 'raw', " +
+            "\"dataType\": \"raw\", " +
-            "data: [" +
+            "\"data\": [" +
             "1140, 1188, 1144, 1172, 1228, 1212, 1236, 1236, 1256, 1320, " +
             "1316, 1280, 1240, 1280, 1324, 1284, 1292, 1268, 1284, 1276, " +
             "1296, 1324, 1308, 1288, 1304, 1276, 1304, 1304, 1276, 1296, " +
@@ -44,8 +47,8 @@ public class SdAnalyserTest {
             "1268, 1292, 1292, 1304, 1288, 1284, 1280, 1276, 1288, 1280, " +
             "1300, 1288, 1320, 1268, 1288, 1280, 1304, 1280, 1280, 1288, " +
             "1292, 1308, 1268, 1292, 1280], " +
-            "HR:57, " +
+            "\"HR\":57, " +
-            "Mute:0 " +
+            "\"Mute\":0 " +
             "}";
 
     @Before
@@ -65,7 +68,7 @@ public class SdAnalyserTest {
     }
 
     @Test
-    public void freq2fftBin() {
+    public void testFreq2fftBin() {
         int n;
         n = sda.freq2fftBin(0.0);
         assertEquals(0,n);
@@ -74,7 +77,7 @@ public class SdAnalyserTest {
     }
 
     @Test
-    public void getMagnitude() {
+    public void testGetMagnitude() {
         double[] fft = {1, 1,
                         2, 1,
                         2, 2};
@@ -87,4 +90,54 @@ public class SdAnalyserTest {
         assertEquals(8.0, m, m * 1e-4);
     }
 
+    @Test
+    public void testGetAccelDataFromJson() {
+        double[] retVal;
+
+        retVal = sda.getAccelDataFromJSON(okJSON);
+        assertNotNull(retVal);
+        assertEquals(125,retVal.length);
+        assertEquals(1140,retVal[0],0.001);
+        assertEquals(1280,retVal[124],0.001);
+    }
+
+
+    @Test
+    public void testGetSpectrumRatio() {
+        double[] okRawVals;
+        double[] alarmRawVals;
+        okRawVals = sda.getAccelDataFromJSON(okJSON);
+        alarmRawVals = sda.getAccelDataFromJSON(alarmJSON);
+
+        double okRatio;
+        double alarmRatio;
+
+        okRatio = sda.getSpectrumRatio(okRawVals);
+        alarmRatio = sda.getSpectrumRatio(alarmRawVals);
+
+        assertTrue("Check Spectrum Ratio for OK data "+okRatio+" is <="+sda.mAlarmRatioThresh,
+                okRatio <= sda.mAlarmRatioThresh);
+        assertTrue("Check Spectrum Ratio for ALARM data "+alarmRatio+" is >"+sda.mAlarmRatioThresh,
+                alarmRatio > sda.mAlarmRatioThresh);
+
+    }
+
+
+    @Test
+    public void testgetAlarmState() {
+        double[] okRawVals;
+        double[] alarmRawVals;
+        okRawVals = sda.getAccelDataFromJSON(okJSON);
+        alarmRawVals = sda.getAccelDataFromJSON(alarmJSON);
+
+        int okAlarmState;
+        int alarmAlarmState;
+
+        okAlarmState = sda.getAlarmState(okRawVals);
+        alarmAlarmState = sda.getAlarmState(alarmRawVals);
+
+        assertEquals("check OK start detected from raw data",0, okAlarmState);
+        assertEquals("check alarm state detected from raw data",1, alarmAlarmState);
+    }
+
 }