From 1b9f5bbaf8f7c6bb36eb0d6493e8a6940a96ebc5 Mon Sep 17 00:00:00 2001
From: Frederik Beimgraben <frederik@beimgraben.net>
Date: Sat, 11 Jan 2025 16:00:44 +0100
Subject: [PATCH] fix: Make already existent functions compliant with the task.

---
 MMS24_25.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 81 insertions(+), 11 deletions(-)

diff --git a/MMS24_25.c b/MMS24_25.c
index 2a048a4..4c339b4 100644
--- a/MMS24_25.c
+++ b/MMS24_25.c
@@ -1,34 +1,104 @@
-//
-// Created by minhd on 03.12.2024.
-//
+/* =========================STYLE-GUIDELINES===========================
+ * All comments use MD-Syntax;
+ * Formulas are written in KaTeX/TeX Syntax.
+ * We adhere by the `kernel.org` style-guidelines.
+ * See: https://www.kernel.org/doc/html/v4.10/process/coding-style.html
+ * =============================AUTHORS================================
+ * Created by Frederik Beimgraben, Minh Dan Cam and Lea Hornberger in
+ * the winter term of 2024/25 at the faculty of computer science at
+ * Reutlingen University.
+ * After grading the full source code will be available at:
+ * 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>
+
+// NULL Pointer
+#ifndef NULL
+#define NULL 0
+#endif
+
+double interpolateLine(
+        double dX1,
+        double dY1,
+        double dX2,
+        double dY2,
+        double dXq
+    ) {
+    double y = (
+        (dY2 - dY1) / (dY2 - dX1)
+    ) * dXq - (
+        (dY2 - dY1) / (dX2 - dX1)
+    ) * dX1 + dY1;
+
+    #ifdef _DEBUG_
+        // DEBUG: print the parameters and result
+        printf("interpolateLine(%lf, %lf, %lf, %lf, %lf) -> %lf\n",
+           dX1,dY1,dX2,dY2,dXq,y);
+    #endif
 
-double interpolateLine(double dX1, double dY1,double dX2, double dY2, double dXq) {
-    double y = ((dY2 - dY1) / (dY2 - dX1)) * dXq + dY1 - ((dY2 - dY1) / (dX2 - dX1)) * dX1;
     return y;
 }
 
-void rescaleDoubleArray(double *pdIn, int iLen, double dMin, double dFactor, double *pdOut) {
-
+void rescaleDoubleArray(
+        double *pdIn,
+        int iLen,
+        double dMin,
+        double dFactor,
+        double *pdOut
+    ) {
+    /* Rescale an array of double values, so that the following rules apply:
+     * Given $ |pdIn| = |pdOut| = iLen $ it should be, that:
+     * $ min(pdIn) > dMin $, as well as
+     * \[ \forall i, j \in (0,\dots,iLen-1):
+     *        (pdOut_i - pdOut_j) = (pdIn_i - pdIn_j) * dFactor \],
+     * which naturally results from:
+     * $ pdOut_i = pdIn_i * dFactor + dMin $
+     */
+    for (int i = 0; i < iLen; i++) {
+        pdOut[i] = pdIn[i] * dFactor + dMin;
+    }
 }
 
-double *generateSineValues(int iNumValues, int iNumSamplesPerPeriod, double dAmp) {
-    double* sineArray = (double*)malloc(iNumValues * sizeof(double));
+double *generateSineValues(
+        int iNumValues,
+        int iNumSamplesPerPeriod,
+        double dAmp
+    ) {
+    /* Generate an array of `iNumValues` double value, so that the values
+     * represent the Y-coordinates of a sine curve of which one full period
+     * occupies `iNumSamplesPerPeriod` values
+     */
+
+    // Initialize the output array
+    double* sineArray = NULL;
+    sineArray = (double*) malloc(sizeof(double) * iNumValues);
+
+    if (sineArray == NULL) {
+        printf("Failed to allocate memory for SineArray\n");
+        exit(-1);
+    }
+
     for (int i=0; i<iNumValues;i++){
         sineArray[i] = dAmp*sin(((2*M_PI)/iNumSamplesPerPeriod) * i);
     }
+
     return sineArray;
 }
 
 void writeDoubleArray(double *pdOut, int iLen, char *pcOutName) {
+    /* Write a list of double values to a file
+     */
+
     FILE* datei = fopen(pcOutName, "w");
     if (datei == NULL) {
-        printf("Fehler beim Öffnen der Datei.\n");
-        return;
+        printf("Error while opening file '%s'.\n", pcOutName);
+        exit(-1);
     }
 
     for (int i = 0; i < iLen; i++) {