added example with filtering

practical_work/rc_circuit/main.c

@@ -29,10 +29,11 @@ int main(int argc, char *argv[]) {
     }
 
     v = v_ini = 1.0;
-    double omega = 10.0;
+    double omega_low = 1.0;
+    double omega = 100.0;
     int i = 0;
     for (double t = 0.0; t < max_t; t += dt) {
-        rc.eps = v_ini * (1.0 + cos(omega * t));
+        rc.eps = v_ini * (1.0 + cos(omega * t) + cos(omega_low * t));
         double ve = exact_solution(t, v_ini, &rc);
         printf("t = %f, v = %f, v_e = %f, diff = %f\n", t, v, ve, ve - v);
         x[i] = t;