ModSim: Finished ass4 code.

modsim/ass2/Makefile

@@ -9,7 +9,7 @@ q%: q%.o
 
 q2: bisection.o
 q3: bisection.o regula_falsi.o newton_raphson.o
-q4: newton_raphson.o
+q4: bisection.o regula_falsi.o newton_raphson.o
 q5: integral.o
 q6: integral.o
 

modsim/ass2/q4.c

@@ -2,9 +2,11 @@
 #include <stdio.h>
 #include <math.h>
 #include "newton_raphson.h"
+#include "bisection.h"
+#include "regula_falsi.h"
 
 #define EPSILON 1e-11
-#define BISEC_STEPS 5
+#define MAX_STEPS 100000
 
 /*
  * Manually define the functions and their derivatives.
@@ -34,14 +36,44 @@ double df3(double x) {
     return (x * x + 1) + 2 * x * (x - 4);
 }
 
-int main(void) {
-    unsigned int steps;
-    double root;
+#define PRINT_ZERO(f, df, x_start) { \
+    if( !isnan(root = newton_raphson(&f, &df, x_start, EPSILON, &steps, MAX_STEPS)) ) \
+        printf(#f ": %.11f (%d steps from start point %.11f)\n", root, steps, (double)x_start); \
+    else \
+        printf(#f ": could not find a root after %d steps\n", steps); \
+}
+
+#define PRINT_ZERO_RANGE(f, df, method, lnbd, ubnd) { \
+    x_start = method(&f, lnbd, ubnd, EPSILON, &start_steps, max_start_steps); \
+    printf("Did first %d steps using " #method "\n", start_steps); \
+    PRINT_ZERO(f, df, x_start); \
+}
+
+int main(int argc, char *argv[]) {
+    unsigned int steps, start_steps, max_start_steps;
+    double root, x_start;
+
+    if( argc != 2 ) {
+        printf("Usage: %s START_STEPS\n", argv[0]);
+        return 1;
+    }
+
+    max_start_steps = atoi(argv[1]);
+
+    PRINT_ZERO(f1, df1, 0);
+    PRINT_ZERO(f2, df2, -10);
+    PRINT_ZERO(f2, df2, 10);
+    PRINT_ZERO(f3, df3, 0);
+
+    printf("\nNow using Bisection to determine the first %d steps.\n\n", max_start_steps);
+
+    PRINT_ZERO_RANGE(f2, df2, bisec, 0, 10);
+    PRINT_ZERO_RANGE(f3, df3, bisec, 0, 10);
+
+    printf("\nNow using Regula Falsi to determine the first %d steps.\n\n", max_start_steps);
 
-    if( !isnan(root = newton_raphson(&f2, &df2, 1000000, EPSILON, &steps, 100000)) )
-        printf("f2: %.11f (%d steps)\n", root, steps);
-    else
-        printf("f2: could not find a root after %d steps\n", steps);
+    PRINT_ZERO_RANGE(f2, df2, regula_falsi, 0, 10);
+    PRINT_ZERO_RANGE(f3, df3, regula_falsi, 0, 10);
 
     return 0;
 }