Add readDoubleArray

MMS24-25.c

@@ -19,11 +19,6 @@
 #include <stdio.h>
 #include <stdarg.h>
 
-// Define NULL if not already provided
-#ifndef NULL
-#define NULL 0
-#endif
-
 void _error(char *fmt, ...) {
     fprintf(stderr, "<\x1B[31;1m ERROR \x1B[0m: \x1B[34m'");
 
@@ -35,7 +30,7 @@ void _error(char* fmt, ...) {
     fprintf(stderr, "'\x1B[0m >\n");
 
 #ifndef _TESTS_NONSTOP
-    exit(-1);
+    exit(EXIT_FAILURE);
 #endif
 }
 
@@ -145,13 +140,45 @@ double *generateSineValues(
 
 void writeDoubleArray(double *pdOut, int iLen, char *pcOutName) {
     // Write a list of double values to a file
-    FILE* datei = fopen(pcOutName, "w");
+    FILE *file = fopen(pcOutName, "w");
-    if (datei == NULL)
+    if (file == NULL)
         _error("writeDoubleArray: Error while opening file '%s'.\n", pcOutName);
 
     for (int i = 0; i < iLen; i++) {
-        fprintf(datei, "%f\n", pdOut[i]);
+        fprintf(file, "%f\n", pdOut[i]);
     }
 
-    fclose(datei);
+    fclose(file);
+}
+
+int readDoubleArray(char *pcInName, double **ppdIn) {
+    char *line = NULL;
+    size_t len = 0;
+    ssize_t read;
+    int i = 0;
+
+    *ppdIn = NULL;
+
+    FILE *file = fopen(pcInName, "r");
+    if (file == NULL)
+        _error("readDoubleArray: Error while opening file '%s'.\n", pcInName);
+
+    while ((read = getline(&line, &len, file)) != -1) {
+        if (*ppdIn == NULL) {
+            *ppdIn = (double*) malloc(sizeof(double));
+        } else {
+            *ppdIn = (double*) realloc(*ppdIn, sizeof(double) *(i+1));
+        }
+
+        if (*ppdIn == NULL)
+            _error("readDoubleArray: Failed to allocate or re-allocate memory for pdIn\n");
+
+        (*ppdIn)[i] = atof(line);
+        i++;
+    }
+
+    free(line);
+    fclose(file);
+
+    return i;
 }

tests.c

@@ -70,7 +70,7 @@ void testInterpolation() {
     success("testInterpolation();");
 }
 
-void testSineAndWriteDoubleArraySingle(int nValues, int dPLen, double dAmp) {
+void testSineAndReadWriteDoubleArraySingle(int nValues, int dPLen, double dAmp) {
     info("Trying: %d, %d, %lf", nValues, dPLen, dAmp);
 
     char* fileName = NULL;
@@ -82,35 +82,57 @@ void testSineAndWriteDoubleArraySingle(int nValues, int dPLen, double dAmp) {
 
     sprintf(fileName, "sine_%d_%d_%lf.results.txt", nValues, dPLen, dAmp);
 
-    writeDoubleArray(
+    double *pdSineValues = generateSineValues(
-        generateSineValues(
         nValues,
         dPLen,
         dAmp
-        ),
+    );
+
+    writeDoubleArray(
+        pdSineValues,
         nValues,
         fileName
     );
 
+    success("Wrote %d values to %s", nValues, fileName);
+
+    double *pdReadValues = NULL;
+    int iReadValues = readDoubleArray(
+        fileName,
+        &pdReadValues
+    );
+
+    if (iReadValues != nValues) {
+        error("Failed to read the correct number of values: %d != %d", iReadValues, nValues);
+    }
+
+    success("Read %d values from %s", iReadValues, fileName);
+
+    for (int i=0; i<nValues; i++) {
+        if (round(pdSineValues[i]*1e6) != round(pdReadValues[i]*1e6)) {
+            error("Failed to read the correct value at index %d: %lf != %lf", i, pdSineValues[i], pdReadValues[i]);
+        }
+    }
+
     info("use `plot \"%s\", \"%s\" with lines` to view.", fileName, fileName);
 
     free(fileName);
 }
 
-void testSineAndWriteDoubleArray() {
+void testSineAndReadWriteDoubleArray() {
     info("testSineAndWriteDoubleArray");
 
-    testSineAndWriteDoubleArraySingle(1000, 300, 1);
+    testSineAndReadWriteDoubleArraySingle(1000, 300, 1);
-    testSineAndWriteDoubleArraySingle(10, 10, 0.5);
+    testSineAndReadWriteDoubleArraySingle(10, 10, 0.5);
-    testSineAndWriteDoubleArraySingle(10, -10, 0.5);
+    testSineAndReadWriteDoubleArraySingle(10, -10, 0.5);
-    testSineAndWriteDoubleArraySingle(10, 10, 0);
+    testSineAndReadWriteDoubleArraySingle(10, 10, 0);
 
     success("testSineAndWriteDoubleArray");
 }
 
 int main (int iArgC, char** ppcArgV){
     testInterpolation();
-    testSineAndWriteDoubleArray();
+    testSineAndReadWriteDoubleArray();
 
     return 0;
 }