All but DFT confirmed

MMS24-25.c

@@ -11,17 +11,16 @@
  * https://git.beimgraben.net/MMS-2024-25/MMS-Loesung-2024-25.git
  */
 
-#include "MMS24-25.h"
-#include "math.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include "MMS24-25.h"
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdlib.h>
+
+#include "MMS24-25.h"
+#include "math.h"
 
 // #region Error Handling and Debugging
 void _error(char *fmt, ...) {
-    fprintf(stderr, "<\x1B[31;1m ERROR \x1B[0m: \x1B[34m'");
+    fprintf(stderr, "< \x1B[31;4;1mERROR\x1B[0m : \x1B[34m'");
 
     va_list args;
     va_start(args, fmt);
@@ -36,7 +35,7 @@ void _error(char *fmt, ...) {
 }
 
 void _debug(char *fmt, ...) {
-    fprintf(stderr, "[\x1B[31;1m DEBUG \x1B[0m] \x1B[34m'");
+    fprintf(stderr, "[ \x1B[37;4;1mDEBUG\x1B[0m ] \x1B[34m'");
 
     va_list args;
     va_start(args, fmt);
@@ -47,7 +46,7 @@ void _debug(char *fmt, ...) {
 }
 
 void _warn(char *fmt, ...) {
-    fprintf(stderr, "[\x1B[33;1m WARN \x1B[0m] \x1B[34m'");
+    fprintf(stderr, "[ \x1B[33;4;1mWARN\x1B[0m ] \x1B[34m'");
 
     va_list args;
     va_start(args, fmt);
@@ -69,9 +68,9 @@ double interpolateLine(
     if (dX2 == dX1)
         _error("interpolateLine: dX1 and dX2 must differ!");
 
-    double y = dY1  *(
+    double y = dY1 * (
         (dX2 - dXq) / (dX2 - dX1)
-    ) + dY2  *(
+    ) + dY2 * (
         (dXq - dX1) / (dX2 - dX1)
     );
 
@@ -99,8 +98,19 @@ void rescaleDoubleArray(
      * which naturally results from:
      * $ pdOut_i = pdIn_i  *dFactor + dMin $
      */
+    // First find the old minimum
+    double dOldMin = pdIn[0];
+    for (int i = 1; i < iLen; i++) {
+        if (pdIn[i] < dOldMin)
+            dOldMin = pdIn[i];
+    }
+
+    // Calculate the offset
+    double dOffset = dMin - dOldMin;
+
+    // Rescale the array
     for (int i = 0; i < iLen; i++) {
-        pdOut[i] = pdIn[i]  *dFactor + dMin;
+        pdOut[i] = pdIn[i] * dFactor + dOffset;
     }
 }
 
@@ -129,13 +139,13 @@ double *generateSineValues(
 
     // Initialize the output array
     double *sineArray = NULL;
-    sineArray = (double*) malloc(sizeof(double)  *iNumValues);
+    sineArray = (double*) malloc(sizeof(double) * iNumValues);
 
     if (sineArray == NULL)
         _error("*generateSineValues: Failed to allocate memory for Sine Array\n");
 
     for (int i=0; i<iNumValues;i++){
-        sineArray[i] = dAmp*sin(((2*M_PI)/iNumSamplesPerPeriod)  *i);
+        sineArray[i] = dAmp * sin(((2*M_PI)/iNumSamplesPerPeriod) * i);
     }
 
     return sineArray;
@@ -147,6 +157,12 @@ void writeDoubleArray(double *pdOut, int iLen, char *pcOutName) {
     if (file == NULL)
         _error("writeDoubleArray: Error while opening file '%s'.\n", pcOutName);
 
+    if (pdOut == NULL)
+        _error("writeDoubleArray: pdOut is NULL\n");
+
+    if (iLen == 0)
+        _warn("writeDoubleArray: iLen is 0\n");
+
     for (int i = 0; i < iLen; i++) {
         fprintf(file, "%f\n", pdOut[i]);
     }
@@ -204,16 +220,58 @@ MMSignal *createSignal() {
     return signal;
 }
 
+LocalExtrema* copyLocalExtrema(LocalExtrema *pexIn) {
+    if (pexIn == NULL)
+        return NULL;
+
+    LocalExtrema *localExtrema = (LocalExtrema*) malloc(sizeof(LocalExtrema));
+    if (localExtrema == NULL)
+        _error("copyLocalExtrema: Failed to allocate memory for localExtrema\n");
+
+    localExtrema->iNumLocalExtrema = pexIn->iNumLocalExtrema;
+    localExtrema->piLocalExtremaPos = (int*) malloc(sizeof(int) *pexIn->iNumLocalExtrema);
+    if (localExtrema->piLocalExtremaPos == NULL)
+        _error("copyLocalExtrema: Failed to allocate memory for localExtrema->piLocalExtremaPos\n");
+
+    for (int i = 0; i < pexIn->iNumLocalExtrema; i++) {
+        localExtrema->piLocalExtremaPos[i] = pexIn->piLocalExtremaPos[i];
+    }
+
+    return localExtrema;
+}
+
+Extrema* copyExtrema(Extrema *pexIn) {
+    if (pexIn == NULL)
+        return NULL;
+
+    Extrema *extrema = (Extrema*) malloc(sizeof(Extrema));
+    if (extrema == NULL)
+        _error("copyExtrema: Failed to allocate memory for extrema\n");
+
+    extrema->iGlobalMinPos = pexIn->iGlobalMinPos;
+    extrema->iGlobalMaxPos = pexIn->iGlobalMaxPos;
+
+    extrema->pexLocalMax = copyLocalExtrema(pexIn->pexLocalMax);
+    extrema->pexLocalMin = copyLocalExtrema(pexIn->pexLocalMin);
+
+    return extrema;
+}
+
 MMSignal *createSignalFromSignal(MMSignal *pmmsIn) {
     MMSignal *signal = createSignal();
 
-    // Initialize and copy the values (deep copy)
+    if (pmmsIn->pdValues != NULL) {
-    signal->pdValues = (double*) malloc(sizeof(double) *pmmsIn->iNumValues);
+        // Initialize and copy the values (deep copy)
-    if (signal->pdValues == NULL)
+        signal->pdValues = (double*) malloc(sizeof(double) *pmmsIn->iNumValues);
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pdValues\n");
+        if (signal->pdValues == NULL)
+            _error("createSignalFromSignal: Failed to allocate memory for signal->pdValues\n");
 
-    for (int i = 0; i < pmmsIn->iNumValues; i++) {
+        for (int i = 0; i < pmmsIn->iNumValues; i++) {
-        signal->pdValues[i] = pmmsIn->pdValues[i];
+            signal->pdValues[i] = pmmsIn->pdValues[i];
+        }
+    } else {
+        _warn("createSignalFromSignal: pmmsIn->pdValues is NULL\n");
+        signal->pdValues = NULL;
     }
 
     // Copy shallow items
@@ -224,38 +282,13 @@ MMSignal *createSignalFromSignal(MMSignal *pmmsIn) {
     signal->dMedian = pmmsIn->dMedian;
 
     // Deep copy of Extrema
-    signal->pexExtrema = (Extrema*) malloc(sizeof(Extrema));
+    if (pmmsIn->pexExtrema == NULL) {
-    if (signal->pexExtrema == NULL)
+        _warn("createSignalFromSignal: pmmsIn->pexExtrema is NULL\n");
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pexExtrema\n");
+        signal->pexExtrema = NULL;
-
+        return signal;
-    signal->pexExtrema->iGlobalMinPos = pmmsIn->pexExtrema->iGlobalMinPos;
-    signal->pexExtrema->iGlobalMaxPos = pmmsIn->pexExtrema->iGlobalMaxPos;
-
-    signal->pexExtrema->pexLocalMax = (LocalExtrema*) malloc(sizeof(LocalExtrema));
-    if (signal->pexExtrema->pexLocalMax == NULL)
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pexExtrema->pexLocalMax\n");
-
-    signal->pexExtrema->pexLocalMax->iNumLocalExtrema = pmmsIn->pexExtrema->pexLocalMax->iNumLocalExtrema;
-    signal->pexExtrema->pexLocalMax->piLocalExtremaPos = (int*) malloc(sizeof(int) *pmmsIn->pexExtrema->pexLocalMax->iNumLocalExtrema);
-    if (signal->pexExtrema->pexLocalMax->piLocalExtremaPos == NULL)
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pexExtrema->pexLocalMax->piLocalExtremaPos\n");
-
-    for (int i = 0; i < pmmsIn->pexExtrema->pexLocalMax->iNumLocalExtrema; i++) {
-        signal->pexExtrema->pexLocalMax->piLocalExtremaPos[i] = pmmsIn->pexExtrema->pexLocalMax->piLocalExtremaPos[i];
     }
 
-    signal->pexExtrema->pexLocalMin = (LocalExtrema*) malloc(sizeof(LocalExtrema));
+    signal->pexExtrema = copyExtrema(pmmsIn->pexExtrema);
-    if (signal->pexExtrema->pexLocalMin == NULL)
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pexExtrema->pexLocalMin\n");
-
-    signal->pexExtrema->pexLocalMin->iNumLocalExtrema = pmmsIn->pexExtrema->pexLocalMin->iNumLocalExtrema;
-    signal->pexExtrema->pexLocalMin->piLocalExtremaPos = (int*) malloc(sizeof(int) *pmmsIn->pexExtrema->pexLocalMin->iNumLocalExtrema);
-    if (signal->pexExtrema->pexLocalMin->piLocalExtremaPos == NULL)
-        _error("createSignalFromSignal: Failed to allocate memory for signal->pexExtrema->pexLocalMin->piLocalExtremaPos\n");
-
-    for (int i = 0; i < pmmsIn->pexExtrema->pexLocalMin->iNumLocalExtrema; i++) {
-        signal->pexExtrema->pexLocalMin->piLocalExtremaPos[i] = pmmsIn->pexExtrema->pexLocalMin->piLocalExtremaPos[i];
-    }
 
     return signal;
 }
@@ -312,6 +345,9 @@ MMSignal *createSignalFromFile(char *pcInName) {
 }
 
 void writeMMSignal(char *pcInName, MMSignal *pmmsIn) {
+    if (pmmsIn->pdValues == NULL)
+        _error("writeMMSignal: pmmsIn->pdValues is NULL\n");
+
     writeDoubleArray(
         pmmsIn->pdValues,
         pmmsIn->iNumValues,
@@ -319,13 +355,32 @@ void writeMMSignal(char *pcInName, MMSignal *pmmsIn) {
     );
 }
 
+void deleteLocalExtrema(LocalExtrema *pexIn) {
+    if (pexIn == NULL)
+        return;
+
+    free(pexIn->piLocalExtremaPos);
+    free(pexIn);
+}
+
+void deleteExtrema(Extrema *pexIn) {
+    if (pexIn == NULL)
+        return;
+
+    deleteLocalExtrema(pexIn->pexLocalMax);
+    deleteLocalExtrema(pexIn->pexLocalMin);
+    free(pexIn);
+}
+
 void deleteSignal(MMSignal *pmmsIn) {
-    free(pmmsIn->pdValues);
+    if (pmmsIn == NULL)
-    free(pmmsIn->pexExtrema->pexLocalMax->piLocalExtremaPos);
+        return;
-    free(pmmsIn->pexExtrema->pexLocalMax);
+
-    free(pmmsIn->pexExtrema->pexLocalMin->piLocalExtremaPos);
+    if (pmmsIn->pdValues != NULL)
-    free(pmmsIn->pexExtrema->pexLocalMin);
+        free(pmmsIn->pdValues);
-    free(pmmsIn->pexExtrema);
+
+    deleteExtrema(pmmsIn->pexExtrema);
+
     free(pmmsIn);
 }
 // #endregion
@@ -335,24 +390,31 @@ double calculateArea(double *pdIn, int iLen) {
     double area = 0;
 
     // #FIXME: Which one should we use according to the task?
-    for (int i = 0; i < iLen-1; i++) {
+    for (int i = 0; i < iLen; i++) {
-        area += (pdIn[i] + pdIn[i+1]) / 2;
+        /* Alternative would be:
+         * area += (pdIn[i] + pdIn[i+1]) / 2;
+         * with i < iLen-1
+         * Which one to use is up to the implemention.
+         */
+        area += pdIn[i];
     }
 
     return area;
 }
 
 double calculateMean(double *pdIn, int iLen) {
-    double mean = 0;
+    /* Here the above defined function `calculateArea` is used to calculate the mean, since:
-
+     * \[ mean(pdIn) = \frac{1}{ |pdIn| } \sum_{i=1}^{ |pdIn| } x_i
-    for (int i = 0; i < iLen; i++) {
+     *               = \frac{area(x)}{ |pdIn| } \]
-        mean += pdIn[i];
+     */
-    }
+    return calculateArea(pdIn, iLen) / iLen;
-
-    return mean / iLen;
 }
 
 double calculateStddev(double *pdIn, int iLen) {
+    /* The standard deviation is calculated as follows:
+     * \[ stddev(pdIn) = \sqrt{ \frac{1}{ |pdIn| } \sum_{i=1}^{ |pdIn| } (x_i - mean(pdIn))^2 } \]
+     */
+
     double mean = calculateMean(pdIn, iLen);
     double stdDev = 0;
 
@@ -363,26 +425,41 @@ double calculateStddev(double *pdIn, int iLen) {
     return sqrt(stdDev / iLen);
 }
 
+double calculateMedian(double *pdIn, int iLen) {
+    /* The median is calculated as follows:
+     * \[ median(pdIn) = \begin{cases}
+     *      pdIn_{\frac{|pdIn|}{2}} & \text{if } |pdIn| \text{ is even} \\
+     *      \frac{pdIn_{\frac{|pdIn|}{2}} + pdIn_{\frac{|pdIn|}{2}+1}}{2} & \text{if } |pdIn| \text{ is odd}
+     * \end{cases} \]
+     */
+
+    if (iLen % 2 == 0) {
+        return pdIn[iLen/2];
+    } else {
+        return (pdIn[iLen/2] + pdIn[iLen/2+1]) / 2;
+    }
+}
+
+LocalExtrema *initLocalExtrema(int iLen) {
+    LocalExtrema *localExtrema = (LocalExtrema*) malloc(sizeof(LocalExtrema));
+    if (localExtrema == NULL)
+        _error("initLocalExtrema: Failed to allocate memory for localExtrema\n");
+
+    localExtrema->iNumLocalExtrema = 0;
+    localExtrema->piLocalExtremaPos = (int*) malloc(sizeof(int) *iLen);
+    if (localExtrema->piLocalExtremaPos == NULL)
+        _error("initLocalExtrema: Failed to allocate memory for localExtrema->piLocalExtremaPos\n");
+
+    return localExtrema;
+}
+
 Extrema *initExtrema(double *pdIn, int iLen) {
     Extrema *extrema = (Extrema*) malloc(sizeof(Extrema));
     if (extrema == NULL)
         _error("initExtrema: Failed to allocate memory for extrema\n");
 
-    extrema->pexLocalMax = (LocalExtrema*) malloc(sizeof(LocalExtrema));
+    extrema->pexLocalMax = initLocalExtrema(iLen);
-    if (extrema->pexLocalMax == NULL)
+    extrema->pexLocalMin = initLocalExtrema(iLen);
-        _error("initExtrema: Failed to allocate memory for extrema->pexLocalMax\n");
-
-    extrema->pexLocalMin = (LocalExtrema*) malloc(sizeof(LocalExtrema));
-    if (extrema->pexLocalMin == NULL)
-        _error("initExtrema: Failed to allocate memory for extrema->pexLocalMin\n");
-
-    extrema->pexLocalMax->piLocalExtremaPos = (int*) malloc(sizeof(int) *iLen);
-    if (extrema->pexLocalMax->piLocalExtremaPos == NULL)
-        _error("initExtrema: Failed to allocate memory for extrema->pexLocalMax->piLocalExtremaPos\n");
-
-    extrema->pexLocalMin->piLocalExtremaPos = (int*) malloc(sizeof(int) *iLen);
-    if (extrema->pexLocalMin->piLocalExtremaPos == NULL)
-        _error("initExtrema: Failed to allocate memory for extrema->pexLocalMin->piLocalExtremaPos\n");
 
     extrema->iGlobalMaxPos = 0;
     extrema->iGlobalMinPos = 0;
@@ -390,14 +467,6 @@ Extrema *initExtrema(double *pdIn, int iLen) {
     return extrema;
 }
 
-void deleteExtrema(Extrema *pexIn) {
-    free(pexIn->pexLocalMax->piLocalExtremaPos);
-    free(pexIn->pexLocalMax);
-    free(pexIn->pexLocalMin->piLocalExtremaPos);
-    free(pexIn->pexLocalMin);
-    free(pexIn);
-}
-
 void initMMSignalFeatures(MMSignal *pmmsIn) {
     pmmsIn->dArea = 0;
     pmmsIn->dMean = 0;
@@ -409,7 +478,13 @@ void initMMSignalFeatures(MMSignal *pmmsIn) {
 Histogram *initHistogram(double *pdIn, int iLen, int iNumBins) {
     Histogram *histogram = (Histogram*) malloc(sizeof(Histogram));
     if (histogram == NULL)
-        _error("initHistogram: Failed to allocate memory for histogram\n");
+        _error("initHistogram: Failed to allocate memory for histogram");
+
+    if (iNumBins == 0)
+        _error("initHistogram: iNumBins must be non-0");
+
+    if (iLen == 0)
+        _warn("initHistogram: iLen is 0\n");
 
     histogram->dIntervalMin = pdIn[0];
     histogram->dIntervalMax = pdIn[0];
@@ -420,26 +495,61 @@ Histogram *initHistogram(double *pdIn, int iLen, int iNumBins) {
             histogram->dIntervalMax = pdIn[i];
     }
 
+    #ifdef _DEBUG_
+    _debug("initHistogram: histogram->dIntervalMin = %lf", histogram->dIntervalMin);
+    _debug("initHistogram: histogram->dIntervalMax = %lf", histogram->dIntervalMax);
+    #endif
+
     histogram->dBinWidth = (histogram->dIntervalMax - histogram->dIntervalMin) / iNumBins;
     histogram->iNumBins = iNumBins;
 
+    #ifdef _DEBUG_
+    _debug("initHistogram: histogram->dBinWidth = %lf", histogram->dBinWidth);
+    #endif
+
+    if (histogram->dBinWidth == 0)
+        histogram->dBinWidth = 1;
+
     histogram->pdBinValues = (double*) malloc(sizeof(double) *iNumBins);
     if (histogram->pdBinValues == NULL)
-        _error("initHistogram: Failed to allocate memory for histogram->pdBinValues\n");
+        _error("initHistogram: Failed to allocate memory for histogram->pdBinValues");
 
     for (int i = 0; i < iNumBins; i++) {
         histogram->pdBinValues[i] = 0;
     }
 
+    for (int i = 0; i < iLen; i++) {
+        int bin = floor((pdIn[i] - histogram->dIntervalMin) / histogram->dBinWidth);
+        if (bin == iNumBins)
+            bin--;
+
+        histogram->pdBinValues[bin]++;
+    }
+
+    for (int i = 0; i < iNumBins; i++) {
+        histogram->pdBinValues[i] /= iLen;
+    }
+
+    #ifdef _DEBUG_
+    // DEBUG: print the parameters and result
+    _debug("initHistogram(%lf, %lf, %lf, %d)",
+        histogram->dIntervalMin,histogram->dIntervalMax,histogram->dBinWidth,histogram->iNumBins);
+    for (int i = 0; i < histogram->iNumBins; i++) {
+        _debug("initHistogram: histogram->pdBinValues[%d] = %lf", i, histogram->pdBinValues[i]);
+    }
+    #endif
+
     return histogram;
 }
 
 void deleteHistogram(Histogram *phIn) {
+    if (phIn == NULL)
+        return;
+
     free(phIn->pdBinValues);
     free(phIn);
 }
 
-// #FIXME: Check if this checks out
 double calculateEntropy(Histogram *phisIn) {
     double entropy = 0;
 
@@ -457,40 +567,49 @@ double calculateEntropy(Histogram *phisIn) {
 // #region Aufgabe 3
 
 MMSignal *convoluteSignals(MMSignal *pmmsInA, MMSignal *pmmsInB) {
-    MMSignal *signal = createSignal();
+    // Calculate output length
+    int iOutLen = pmmsInA->iNumValues + pmmsInB->iNumValues - 1;
 
-    if (pmmsInA->iNumValues != pmmsInB->iNumValues)
+    double *pdOut = (double*) malloc(sizeof(double) *iOutLen);
-        _error("convoluteSignals: Signals must have the same length\n");
+    if (pdOut == NULL)
+        _error("convoluteSignals: Failed to allocate memory for pdOut\n");
 
-    signal->pdValues = (double*) malloc(sizeof(double) *pmmsInA->iNumValues);
+    for (int i = 0; i < iOutLen; i++) {
-    if (signal->pdValues == NULL)
+        pdOut[i] = 0;
-        _error("convoluteSignals: Failed to allocate memory for signal->pdValues\n");
-
-    for (int i = 0; i < pmmsInA->iNumValues; i++) {
-        signal->pdValues[i] = pmmsInA->pdValues[i] * pmmsInB->pdValues[i];
     }
 
-    signal->iNumValues = pmmsInA->iNumValues;
+    for (int i = 0; i < pmmsInA->iNumValues; i++) {
+        for (int j = 0; j < pmmsInB->iNumValues; j++) {
+            pdOut[i+j] += pmmsInA->pdValues[i] * pmmsInB->pdValues[j];
+        }
+    }
+
+    MMSignal *signal = createSignalFromDoubleArray(iOutLen, pdOut);
+    initMMSignalFeatures(signal);
 
     return signal;
 }
 
 // #FIXME: Check if this checks out
 MMSignal *getPascalLine(int iLinenum) {
-    MMSignal *signal = createSignal();
+    if (iLinenum <= 0)
+        _error("getPascalLine: iLinenum must be greater than 0\n");
 
-    signal->pdValues = (double*) malloc(sizeof(double) *iLinenum);
+    // Calculate a kernel signal using pascales triangle without using the factorial
-    if (signal->pdValues == NULL)
+    double *pdValues = NULL;
-        _error("getPascalLine: Failed to allocate memory for signal->pdValues\n");
+    pdValues = (double*) malloc(sizeof(double) * iLinenum);
+    if (pdValues == NULL)
+        _error("getPascalLine: Failed to allocate memory for pdValues\n");
 
-    signal->pdValues[0] = 1;
+    for (int i = 0; i < iLinenum; i++) {
-    signal->pdValues[iLinenum-1] = 1;
+        pdValues[i] = 1;
-
+        for (int j = i-1; j > 0; j--) {
-    for (int i = 1; i < iLinenum-1; i++) {
+            pdValues[j] = pdValues[j] + pdValues[j-1];
-        signal->pdValues[i] = signal->pdValues[i-1] *(iLinenum-i) / i;
+        }
     }
 
-    signal->iNumValues = iLinenum;
+    MMSignal *signal = createSignalFromDoubleArray(iLinenum, pdValues);
+    initMMSignalFeatures(signal);
 
     return signal;
 }
@@ -498,10 +617,12 @@ MMSignal *getPascalLine(int iLinenum) {
 // #endregion
 
 // #region Aufgabe 4
-void computeDFT(int iLen,
+void computeDFT(
-		double *pdRealIn, double *pdImgIn,
+        int iLen,
-		double *pdRealOut, double *pdImgOut,
+    	double *pdRealIn, double *pdImgIn,
-		int iDirection /*-1,1*/) {
+    	double *pdRealOut, double *pdImgOut,
+    	int iDirection
+    ) {
 	// Check the value of iDirection
 	if (iDirection != -1 && iDirection != 1)
         _error("computeDFT: iDirection must be either -1 or 1\n");
@@ -509,9 +630,21 @@ void computeDFT(int iLen,
 	for (int k = 0; k < iLen; k++) {
         pdRealOut[k] = 0;
         pdImgOut[k] = 0;
+
+        // Compute the sum for the k-th output element
         for (int n = 0; n < iLen; n++) {
-            pdRealOut[k] += pdRealIn[n] * cos(2*M_PI *k *n / iLen) + iDirection * pdImgIn[n] * sin(2*M_PI *k *n / iLen);
+            double angle = iDirection * 2.0 * M_PI * k * n / iLen;
-            pdImgOut[k] += -iDirection * pdRealIn[n] * sin(2*M_PI *k *n / iLen) + pdImgIn[n] * cos(2*M_PI *k *n / iLen);
+            double cosTerm = cos(angle);
+            double sinTerm = sin(angle);
+
+            pdRealOut[k] += pdRealIn[n] * cosTerm - pdImgIn[n] * sinTerm;
+            pdImgOut[k] += pdRealIn[n] * sinTerm + pdImgIn[n] * cosTerm;
+        }
+
+        // Normalize the output
+        if (iDirection == -1) {
+            pdRealOut[k] /= iLen;
+            pdImgOut[k] /= iLen;
         }
     }
 }

MMS24-25.h

@@ -91,6 +91,6 @@ void computeDFT(int iLen,
 		double *pdRealIn, double *pdImgIn,
 		double *pdRealOut, double *pdImgOut,
 		int iDirection /*-1,1*/);
-void convertCart2Polar(double *pdRealIn, double *pdImgIn,double *pdRadiusOut, double *pdAngleOut, int iLen);
+void convertCart2Polar(double *pdRealIn, double *pdImgIn, double *pdRadiusOut, double *pdAngleOut, int iLen);
-void convertPolar2Cart(double *pdRadiusIn, double *pdAngleIn, double *pdRealOut, double *pdImgOut,int iLen);
+void convertPolar2Cart(double *pdRadiusIn, double *pdAngleIn, double *pdRealOut, double *pdImgOut, int iLen);
 #endif

Makefile

@@ -1,6 +1,6 @@
 CC=gcc
 SOURCE_FILE=MMS24-25.c
-OPTS=-lm -D _TESTS_NONSTOP
+OPTS=-lm -D _DEBUG_
 
 all: clean tests run
 
@@ -11,4 +11,4 @@ tests:
 	$(CC) tests.c $(SOURCE_FILE) -o tests $(OPTS)
 
 run:
-	./tests
+	./tests

tests.c

@@ -44,8 +44,8 @@ void error(const char* fmt, ...) {
 void testInterpolation() {
     info("testInterpolation");
 
-    double dRangeMin = -3;
+    double dRangeMin = -1;
-    double dRangeMax = 3;
+    double dRangeMax = 1;
     double dRangeStep = 0.33;
 
     for (double dX1=dRangeMin;dX1<dRangeMax;dX1+=dRangeStep) {
@@ -117,6 +117,8 @@ void testSineAndReadWriteDoubleArraySingle(int nValues, int dPLen, double dAmp)
     info("use `plot \"%s\", \"%s\" with lines` to view.", fileName, fileName);
 
     free(fileName);
+    free(pdSineValues);
+    free(pdReadValues);
 }
 
 void testSineAndReadWriteDoubleArray() {
@@ -130,9 +132,323 @@ void testSineAndReadWriteDoubleArray() {
     success("testSineAndWriteDoubleArray");
 }
 
+void testCreateSignalWithDefault() {
+    info("testCreateSignalWithDefault");
+
+    MMSignal *signal = createSignalWithDefault(10, M_PI);
+
+    if (signal->iNumValues != 10) {
+        error("Failed to create signal with 10 values: %d != 10", signal->iNumValues);
+    }
+
+    for (int i=0; i<10; i++) {
+        if (signal->pdValues[i] != M_PI) {
+            error("Failed to create signal with default value 0 at index %d: %lf != 0", i, signal->pdValues[i]);
+        }
+    }
+
+    success("testCreateSignalWithDefault");
+
+    deleteSignal(signal);
+}
+
+void testCreateSignalFromDoubleArray() {
+    info("testCreateSignalFromDoubleArray");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    MMSignal *signal = createSignalFromDoubleArray(10, pdValues);
+
+    if (signal->iNumValues != 10) {
+        error("Failed to create signal with 10 values: %d != 10", signal->iNumValues);
+    }
+
+    for (int i=0; i<10; i++) {
+        if (signal->pdValues[i] != pdValues[i]) {
+            error("Failed to create signal with default value 0 at index %d: %lf != 0", i, signal->pdValues[i]);
+        }
+    }
+
+    success("testCreateSignalFromDoubleArray");
+
+    deleteSignal(signal);
+}
+
+void testCreateSignalFromFile() {
+    info("testCreateSignalFromFile");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    char* fileName = "testCreateSignalFromFile.results.txt";
+
+    writeDoubleArray(pdValues, 10, fileName);
+
+    MMSignal *signal = createSignalFromFile(fileName);
+
+    if (signal->iNumValues != 10) {
+        error("Failed to create signal with 10 values: %d != 10", signal->iNumValues);
+    }
+
+    for (int i=0; i<10; i++) {
+        if (signal->pdValues[i] != pdValues[i]) {
+            error("Failed to create signal with default value 0 at index %d: %lf != 0", i, signal->pdValues[i]);
+        }
+    }
+
+    success("testCreateSignalFromFile");
+
+    deleteSignal(signal);
+}
+
+void testWriteMMSignal() {
+    info("testWriteMMSignal");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    char* fileName = "testWriteMMSignal.results.txt";
+
+    MMSignal *signal = createSignalFromDoubleArray(10, pdValues);
+
+    writeMMSignal(fileName, signal);
+
+    MMSignal *readSignal = createSignalFromFile(fileName);
+
+    if (signal->iNumValues != readSignal->iNumValues) {
+        error("Failed to read the correct number of values: %d != %d", signal->iNumValues, readSignal->iNumValues);
+    }
+
+    for (int i=0; i<10; i++) {
+        if (signal->pdValues[i] != readSignal->pdValues[i]) {
+            error("Failed to read the correct value at index %d: %lf != %lf", i, signal->pdValues[i], readSignal->pdValues[i]);
+        }
+    }
+
+    deleteSignal(signal);
+    deleteSignal(readSignal);
+
+    success("testWriteMMSignal");
+}
+
+void testCalculateArea() {
+    info("testCalculateArea");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    double dArea = calculateArea(pdValues, 10);
+
+    if (round(dArea*1e6) != 55e6) {
+        error("Failed to calculate the correct area: %lf != 55", dArea);
+    }
+
+    success("testCalculateArea");
+}
+
+void testCalculateMean() {
+    info("testCalculateMean");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    double dMean = calculateMean(pdValues, 10);
+
+    if (round(dMean*1e6) != 5.5e6) {
+        error("Failed to calculate the correct mean: %lf != 5.5", dMean);
+    }
+
+    success("testCalculateMean");
+}
+
+void testCalculateStdDev() {
+    info("testCalculateStdDev");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    double dStdDev = calculateStddev(pdValues, 10);
+
+    if (round(dStdDev*1e6) != 2.872281e6) {
+        error("Failed to calculate the correct standard deviation: %lf != 2.872281", dStdDev);
+    }
+
+    success("testCalculateStdDev");
+}
+
+void testCalculateMedian() {
+    info("testCalculateMedian");
+
+    double pdValues[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    double dMedian = calculateMedian(pdValues, 10);
+
+    if (dMedian != 6) {
+        error("Failed to calculate the correct median: %lf != 5.5", dMedian);
+    }
+
+    success("testCalculateMedian");
+}
+
+void testCalculateEntropy() {
+    info("testCalculateEntropy");
+
+    double pdValues[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    Histogram *histogram = initHistogram(pdValues, 11, 11);
+
+    double dEntropy = calculateEntropy(histogram);
+
+    if (round(dEntropy*1e6) != 3.459432e6) { // Should be log2(1/11) = 3.459432
+        error("Failed to calculate the correct entropy: %lf != 3.459432", dEntropy);
+    }
+
+    success("testCalculateEntropy");
+}
+
+void testConvoluteSignals() {
+    info("testConvoluteSignals");
+
+    double pdValues1[] = {1, 2, 3, 4, 5};
+    double pdValues2[] = {1, 2, 3, 4, 5};
+
+    MMSignal *signal1 = createSignalFromDoubleArray(5, pdValues1);
+    MMSignal *signal2 = createSignalFromDoubleArray(5, pdValues2);
+
+    MMSignal *signal3 = convoluteSignals(signal1, signal2);
+
+    if (signal3->iNumValues != 9) {
+        error("Failed to calculate the correct number of values: %d != 9", signal3->iNumValues);
+    }
+
+    double pdExpectedValues[] = {1, 4, 10, 20, 35, 44, 46, 40, 25};
+
+    for (int i=0; i<9; i++) {
+        if (signal3->pdValues[i] != pdExpectedValues[i]) {
+            error("Failed to calculate the correct value at index %d: %lf != %lf", i, signal3->pdValues[i], pdExpectedValues[i]);
+        }
+    }
+
+    success("testConvoluteSignals");
+}
+
+void testGetPascalLine() {
+    info("testGetPascalLine");
+
+    // For 5
+    MMSignal *signal = getPascalLine(5);
+
+    if (signal->iNumValues != 5) {
+        error("Failed to calculate the correct number of values: %d != 5", signal->iNumValues);
+    }
+
+    double pdExpectedValues[] = {1, 4, 6, 4, 1};
+
+    for (int i=0; i<5; i++) {
+        if (signal->pdValues[i] != pdExpectedValues[i]) {
+            error("Failed to calculate the correct value at index %d: %lf != %lf", i, signal->pdValues[i], pdExpectedValues[i]);
+        }
+    }
+
+    // For 1
+    signal = getPascalLine(1);
+
+    if (signal->iNumValues != 1) {
+        error("Failed to calculate the correct number of values: %d != 1", signal->iNumValues);
+    }
+
+    if (signal->pdValues[0] != 1) {
+        error("Failed to calculate the correct value at index 0: %lf != 1", signal->pdValues[0]);
+    }
+
+    // For 11
+    signal = getPascalLine(11);
+
+    if (signal->iNumValues != 11) {
+        error("Failed to calculate the correct number of values: %d != 11", signal->iNumValues);
+    }
+
+    double pdExpectedValues11[] = {1, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1};
+
+    for (int i=0; i<11; i++) {
+        if (signal->pdValues[i] != pdExpectedValues11[i]) {
+            error("Failed to calculate the correct value at index %d: %lf != %lf", i, signal->pdValues[i], pdExpectedValues11[i]);
+        }
+    }
+
+    success("testGetPascalLine");
+}
+
+void testComputeDFT() {
+    info("testComputeDFT");
+
+    double pdRealIn[] = {1, 2, 3, 4, 5};
+    double pdImgIn[] = {1, 2, 3, 4, 5};
+
+    double pdRealOut[5];
+    double pdImgOut[5];
+
+    computeDFT(5, pdRealIn, pdImgIn, pdRealOut, pdImgOut, 1);
+
+    for (int i=0; i<5; i++) {
+        if (pdImgOut[i] < 0) {
+            printf("%lf - %lfi\n", pdRealOut[i], -pdImgOut[i]);
+        } else {
+            printf("%lf + %lfi\n", pdRealOut[i], pdImgOut[i]);
+        }
+    }
+
+    success("testComputeDFT");
+}
+
+void testConvertCart2Polar() {
+    // convertCart2Polar(double *pdRealIn, double *pdImgIn, double *pdRadiusOut, double *pdAngleOut, int iLen)
+    info("testConvertCart2Polar");
+
+    double pdRealIn[] = {1, 0, 1, -1, 0};
+    double pdImgIn[] = {0, 1, 1, 0, -1};
+    double pdRadiusOut[5];
+    double pdAngleOut[5];
+
+    convertCart2Polar(pdRealIn, pdImgIn, pdRadiusOut, pdAngleOut, 5);
+
+    for (int i=0; i<5; i++) {
+        printf("%lf + %lfi -> r=%lf / θ=%lfπ\n", pdRealIn[i], pdImgIn[i], pdRadiusOut[i], pdAngleOut[i] / M_PI);
+    }
+
+    success("testConvertCart2Polar");
+}
+
+void testConvertPolar2Cart() {
+    // convertPolar2Cart(double *pdRadiusIn, double *pdAngleIn, double *pdRealOut, double *pdImgOut, int iLen)
+    info("testConvertPolar2Cart");
+
+    double pdRadiusIn[] = {1, 1, 1, 1, 1};
+    double pdAngleIn[] = {0, M_PI/2, M_PI, 3*M_PI/2, 2*M_PI};
+    double pdRealOut[5];
+    double pdImgOut[5];
+
+    convertPolar2Cart(pdRadiusIn, pdAngleIn, pdRealOut, pdImgOut, 5);
+
+    for (int i=0; i<5; i++) {
+        printf("r=%lf / θ=%lfπ -> %lf + %lfi\n", pdRadiusIn[i], pdAngleIn[i] / M_PI, pdRealOut[i], pdImgOut[i]);
+    }
+
+    success("testConvertPolar2Cart");
+}
+
 int main (int iArgC, char** ppcArgV){
     testInterpolation();
     testSineAndReadWriteDoubleArray();
+    testCreateSignalWithDefault();
+    testCreateSignalFromDoubleArray();
+    testCreateSignalFromFile();
+    testWriteMMSignal();
+    testCalculateArea();
+    testCalculateMean();
+    testCalculateStdDev();
+    testCalculateMedian();
+    testCalculateEntropy();
+    testConvoluteSignals();
+    testGetPascalLine();
+    testComputeDFT();
+    testConvertCart2Polar();
+    testConvertPolar2Cart();
 
     return 0;
 }