//This is a function that computes dewpoint
//Written by Max Indelicato and Adam Plumb

#include <iostream.h>
#include <fstream.h>
#include <math.h>
#include <iomanip.h>
#include <math.h>

void dewpoint(ofstream outfile)
{
	double Spd, T, sum, ten_min, average, JD, pressure, blah;	//declares variables as data type double
	int real_info, bad, loop_count, day;//declares variables as data type int

	double Td, RH, K, Td2;
	const double Rv = 461.5;

	ifstream inputfile;											//declares inputfile
									
	inputfile.open("89381099.txt");								//opens input text file (varies)
	inputfile.ignore(500, '\n');								//ignores first line of inputfile
	inputfile.ignore(500, '\n');								//ignores second line of inputfile

	day = 1;													//initializes day as equaling 1
	outfile << "\n\n\n";
	outfile << "DAY" << "            " << "DEWPOINT" << "             " << "# OF ERRORS" << endl;    //outputs labels of ouputfile 
	outfile << "------------------------------------------------------------------------------"<> JD;										//gets initial Julian Day
		
		while(loop_count <= 144)								//initiates loop
		{
			inputfile >> ten_min >> T >> pressure >> Spd >> blah >> RH;		//reading in file
			inputfile.ignore(500, '\n');						//ignores the rest of the line

			if(pressure != 444.0 && T != 444.0 && RH != 444.0)	//If statement
			{	
				K = T + 273.15;									//computing kelvin
			
				Td = ((1/K) - (Rv * log(RH))/(2500800 - 2397.5 * (K - 273.15)));
				Td2 = pow(Td, -1);
                                sum = sum + Td2;										//adding a total
				real_info++;										//counting number of times		
			}


			else													//else statement
				bad++;
		
			loop_count++;											//adding 1 to loop_count
			
			inputfile >> JD;										//reading in JD


		}	//end of inside while loop

		
		average = sum / real_info;									//gets average
	
		outfile << setiosflags(ios::showpoint | ios::fixed);		//declaring iosflags
		outfile << setprecision(5);								//sets precision to 2
		//outputs data to file
		outfile << setw(2)<< day << setw(21) << average << setw(25) << bad << endl;

		//adds one to day
		day++;
	}		//end of outside while loop


}