day4

Code/Parallel/mpi/my_pi.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <time.h>
+#include <math.h>
+
+int main(int argc, char **argv)
+{
+    int i, intervals = 10000000;
+    double truePi = 3.141592653589793238462643;
+    double x, dx, f, sum, pi;
+    double time2;
+
+    time_t time1 = clock();
+
+    printf("Number of intervals: %d\n", intervals);
+
+    sum = 0.0;
+    dx = 1.0 / (double) intervals;
+
+    for (i = 1; i <= intervals; i++) {
+        x = dx * ((double) (i - 0.5));
+        f = 4.0 / (1.0 + x*x);
+        sum = sum + f;
+    }
+
+    pi = dx*sum;
+
+    time2 = (clock() - time1) / (double) CLOCKS_PER_SEC;
+
+    printf("Computed PI %f\n", pi);
+    printf("The true PI %f\n\n", truePi);
+    printf("Elapsed time (s) = %f\n", time2);
+
+    return 0;
+}