Read a freqency from an analog pin

Using Arduino Programming Questions
23

Now ,it is correct?

#include <FreqCounter.h>

double frequency;


void setup() {
  pinMode(5,OUTPUT);
  pinMode(11,OUTPUT);
  pinMode(12,OUTPUT);
  pinMode(15,OUTPUT);
  pinMode(16,OUTPUT);
  pinMode(17,OUTPUT);

}



void loop() {
  long getFrequency(A0);
   { 
     #define SAMPLES 4096 
     long freq = 0; 
     for(unsigned int j=0; j<SAMPLES; j++)
     {
        freq+= 500000/pulseIn(A0, HIGH, 250000);
     } 
     frequency = freq/SAMPLES;
     if (frequency <5000)
     {
       digitalWrite(5, HIGH);
       digitalWrite(11,HIGH);
     }
     if (frequency >5000)
     {
       digitalWrite(12, HIGH);
       digitalWrite(15,HIGH);
     }              
  }
  
}