Added other tests

Added tests for:
-Average (all cases)
-STD (all cases)
-Anomaly detection (on a uniform distribution)

include/dataAcquisition.h

@@ -6,7 +6,7 @@
 #include <stdlib.h>
 
 void initializeReadings();
-void freeReadings();
+bool freeReadings();
 
 int getSensorsNumber();
 int getSlidingWindowSize();
@@ -20,6 +20,12 @@ float getOverallAverage();
 
 float getStandardDeviationOnSensor(int sensorIndex);
 float getStandardDeviationOnAllSensors();
-float getStandardDeviationOnAllSensors();
+float getOverallStandardDeviation();
+
+float getLastReading(int sensorIndex);
+
+bool anomalyDetect(float average, float standardDeviation);
+
+int getOutlierCount();
 
 #endif // DATA_ACQUISITION_H

libraries/dataAcquisition.c

@@ -3,6 +3,8 @@
 #include <stdbool.h>
 #include <math.h>
 
+int outlierCount;
+
 // Variable definition
 static float **readings;
 static int sensorsNumber;
@@ -35,11 +37,19 @@ void initializeReadings(int numSensors, int windowSize) {
     setSlidingWindowSize(windowSize);
 }
 
-void freeReadings() {
+bool freeReadings() {
     for (int i = 0; i < sensorsNumber; i++) {
         free(readings[i]);
     }
-    free(readings);
+    
+    if(readings != NULL){
+        free(readings);
+        return true;
+    }
+    else{
+        return false;
+    }
+    
 }
 
 // Functions
@@ -64,6 +74,14 @@ bool isFull(int sensorIndex) {
     return true;
 }
 
+float getLastReading(int sensorIndex) {
+    if (isFull(sensorIndex)) {
+        return readings[sensorIndex][slidingWindowSize - 1];
+    } else {
+        return readings[sensorIndex][0];
+    }
+}
+
 // Add a reading to the readings array
 void addReading(float value, int sensorIndex) {
     if (isFull(sensorIndex)) {
@@ -75,6 +93,8 @@ void addReading(float value, int sensorIndex) {
         for (int i = 0; i < slidingWindowSize; i++) {
             if (readings[sensorIndex][i] == 0) {
                 readings[sensorIndex][i] = value;
+                // Update the position index
+                
                 break;
             }
 
@@ -99,7 +119,7 @@ float getAverageOnSensor(int sensorIndex) {
 float getAverageOnAllSensors() {
     float sum = 0;
     for (int i = 0; i < sensorsNumber; i++) {
-        sum += getAverageOnSensor(i);
+        sum += getLastReading(i);
     }
     return sum / sensorsNumber;
 }
@@ -137,15 +157,33 @@ float getStandardDeviationOnSensor(int sensorIndex) {
 
 float getStandardDeviationOnAllSensors() {
     float sum = 0;
+    float average = getAverageOnAllSensors();
     for (int i = 0; i < sensorsNumber; i++) {
-        sum += getStandardDeviationOnSensor(i);
+        float lastReading = getLastReading(i);
+        sum += pow(lastReading - average, 2);
     }
-    return sum / sensorsNumber;
+
+    return sqrt(sum / sensorsNumber);
+}
+
+void anomalyDetect(float average, float standardDeviation) {
+    float upperThreshold = average + 2.17 * standardDeviation; // 97% confidence interval
+    float lowerThreshold = average - 2.17 * standardDeviation; // Lower bound for anomaly detection
+    outlierCount = 0;
+    for (int i = 0; i < sensorsNumber; i++) {
+        for (int j = 0; j < slidingWindowSize; j++) {
+            if (readings[i][j] > upperThreshold || readings[i][j] < lowerThreshold) {
+                outlierCount++;
+            }
+        }
+    }
+    
 }
 
 float getOverallStandardDeviation() {
     float sum = 0;
     int totalReadings = 0;
+    float totalAverage = getOverallAverage();
     for (int i = 0; i < sensorsNumber; i++) {
         if (!isFull(i)) {
             printf("The sliding window for sensor %d is not full\n", i);
@@ -156,5 +194,14 @@ float getOverallStandardDeviation() {
             totalReadings++;
         }
     }
-    return sqrt(sum / totalReadings);
+
+    float totalStandardDeviation = sqrt(sum / totalReadings);
+
+    anomalyDetect(totalAverage, totalStandardDeviation);
+
+    return totalStandardDeviation;
+}
+
+int getOutlierCount() {
+    return outlierCount;
 }

test/test_dataAcquisition.c

@@ -3,14 +3,105 @@
 #include <math.h>
 #include "../include/dataAcquisition.h"
 
+#define NUMBER_OF_SENSORS 5
+#define SLIDING_WINDOW_SIZE 10
+
+#define AVERAGE_UNCERTAINTY 0.01
+#define STD_UNCERTAINTY 0.01
+
+// Testing the inizialization and the instanciacion of the sensors' number and sliding window size
 void test_initializeReadings() {
-    initializeReadings(5, 100);
-    assert(getSensorsNumber() == 5);
-    assert(getSlidingWindowSize() == 100);
+    initializeReadings(NUMBER_OF_SENSORS, SLIDING_WINDOW_SIZE);
+    assert(getSensorsNumber() == NUMBER_OF_SENSORS);
+    assert(getSlidingWindowSize() == SLIDING_WINDOW_SIZE);
 }
 
+// Testing the logic of add readings to see if the slidinw window is full
+void test_addReading() {
+    for (int sensor = 0; sensor < NUMBER_OF_SENSORS; sensor++) {
+        for (int value = 1; value <= SLIDING_WINDOW_SIZE; value++) {
+            addReading(value, sensor);
+        }
+    }
+    assert(isFull(NUMBER_OF_SENSORS-1) == true); // Assuming the last sensor acquired the data
+}
+
+// Testing the logic of average methods
+void test_averageOnSensor() {
+    printf("Average on sensor %d: %f\n", NUMBER_OF_SENSORS-1, getAverageOnSensor(NUMBER_OF_SENSORS-1));
+    float average = getAverageOnSensor(NUMBER_OF_SENSORS-1);
+    float expected_average = (SLIDING_WINDOW_SIZE + 1) / 2.0;
+    assert(fabs(average - expected_average) < AVERAGE_UNCERTAINTY);
+}
+
+void test_standardDeviationOnSensor() {
+    printf("Standard deviation on sensor %d: %f\n", NUMBER_OF_SENSORS-1, getStandardDeviationOnSensor(NUMBER_OF_SENSORS-1));
+    float standard_deviation = getStandardDeviationOnSensor(NUMBER_OF_SENSORS-1);
+    float expected_standard_deviation = 2.872281323269;
+    assert(fabs(standard_deviation - expected_standard_deviation) < STD_UNCERTAINTY);
+}
+
+void test_averageOnAllSensors() {
+    printf("Average on all sensors: %f\n", getAverageOnAllSensors());
+    float average = getAverageOnAllSensors();
+    float expected_average = SLIDING_WINDOW_SIZE;
+    assert(fabs(average - expected_average) < AVERAGE_UNCERTAINTY);
+}
+
+void test_standardDeviationOnAllSensors() {
+    printf("Standard deviation on all sensors: %f\n", getStandardDeviationOnAllSensors());
+    float standard_deviation = getStandardDeviationOnAllSensors();
+    float expected_standard_deviation = 0;
+    assert(fabs(standard_deviation - expected_standard_deviation) < STD_UNCERTAINTY);
+}
+
+void test_overallAverage(){
+    printf("Overall average on all sensors: %f\n", getOverallAverage());
+    float average = getOverallAverage();
+    float expected_overall_average = (SLIDING_WINDOW_SIZE + 1) / 2.0;
+    assert(fabs(average - expected_overall_average) < AVERAGE_UNCERTAINTY);
+}
+
+void test_overallStandardDeviation(){
+    printf("Overall standard deviation: %f\n", getOverallStandardDeviation());
+    float standard_deviation = getStandardDeviationOnSensor(NUMBER_OF_SENSORS-1);
+    float expected_standard_deviation = 2.872281323269;
+    assert(fabs(standard_deviation - expected_standard_deviation) < STD_UNCERTAINTY);
+}
+
+void test_anomalyDetect(){
+    float average = getOverallAverage();
+    float standard_deviation = getOverallStandardDeviation();
+    anomalyDetect(average, standard_deviation);
+    printf("Outlier count: %i\n", getOutlierCount());
+    assert(fabs(getOutlierCount() - 0) < 0.01);
+
+    // Adding an outlier
+    addReading(20, NUMBER_OF_SENSORS-1);
+    average = getOverallAverage();
+    standard_deviation = getOverallStandardDeviation();
+    anomalyDetect(average, standard_deviation);
+    printf("Outlier count: %i\n", getOutlierCount());
+    assert(fabs(getOutlierCount() - 1) < 0.01);
+}
+
+// TODO: Test all the functions with a normal distribution
+
+// TODO: Evaluate the normal distribution with the anomaly detection
+void test_freeReadings() {
+    assert(freeReadings() == true);
+}
 
 int main() {
     test_initializeReadings();
+    test_addReading();
+    test_averageOnSensor();
+    test_standardDeviationOnSensor();
+    test_averageOnAllSensors();
+    test_standardDeviationOnAllSensors();
+    test_overallAverage();
+    test_overallStandardDeviation();
+    test_anomalyDetect();
+    test_freeReadings();
     return 0;
 }