/* Create a FITS file, using cfitsio and some casacore libraries
   by Samuel George 
   21-11-2011
   Compile: g++ build_fits.cpp -o build_fits -lcasa_casa -lcfitsio
*/
#include <iostream> // STL iostream
#include <string>
#include <cmath>

extern "C"{
#include <fitsio.h>
}

using std::cerr;
using std::cout;
using std::endl;
using std::string;

int main()
{
	cout << "Create a FITS file" << endl;
	int lenTime(10), status (0), lenFreq(20);
	long naxis(2), naxes[2] = {lenTime,lenFreq};
	long nelements (lenTime*lenFreq);
	long fpixel (1), exposure (1500);
	char comment[] ="Total Exposure Time";
	cout << comment << endl;
	float pixels[lenFreq][lenTime];
	// create an array of pixels 
	try {
		for (int ii(0); ii < lenTime; ii++){
			for (int jj(0); jj <lenFreq; jj++){
				pixels[jj][ii] = 10.0*(ii+jj);
			}
		}
	} catch (string message) {
		cerr << "Error creating pixel array" << message << endl;
	}

	try { // write the image to a fits file...
		fitsfile *fptr;
		fits_create_file (&fptr, "!output.fits", &status);
		fits_create_img (fptr, FLOAT_IMG,naxis,naxes,&status);
		/* Write a keyword - its the address you pass */
		fits_update_key(fptr,TLONG,"EXPOSURE",&exposure,comment,&status);
		//write an array to the image
		fits_write_img(fptr, TFLOAT, fpixel, nelements, pixels[0],&status);
		fits_close_file(fptr,&status);
		status = 0 ;
	} catch (std::string message) {
		cerr << message << endl;
	}
}