UPDATE_CELL_DATA = 0;

data_rows  	 = Columns 	(SELECTED_CHART_ROWS);

if (data_rows % 2 == 0)
{
	temp = -1;
	data_columns = -1;
	
	for (count = 0; count<data_rows; count = count+1)
	{
		temp2 = SELECTED_CHART_COLS[count];
		if (temp<0)
		{
			temp = temp2;
		}
		else
		{
			if (temp!=temp2)
			{
				if (data_columns<0)
				{
					data_columns = temp2;
				}
				else
				{
					if (temp2!=data_columns)
					{
						break;
					}
				}
			}
		}
	}
	
	if ((count == data_rows)&&(data_columns>=0)&&(temp>=0))
	{
		for (count = 0; count < data_rows; count = count+2)
		{
			if (SELECTED_CHART_ROWS[count]!=SELECTED_CHART_ROWS[count+1])
			{
				break;
			}
		}
	
		if (count==data_rows)
		{
		
			SELECTED_CHART_ROWS = {2,data_rows/2};
			for (count = 0; count < data_rows; count = count+2)
			{
				SELECTED_CHART_ROWS[0][count/2]=SELECTED_CHART_DATA[count];
				SELECTED_CHART_ROWS[1][count/2]=SELECTED_CHART_DATA[count+1];
			}
			SELECTED_CHART_DATA = SELECTED_CHART_ROWS;
			data_rows = data_rows/2;
			
			sx = 0;
			sy = 0;
			ss = data_rows;
			for (count = 0; count<data_rows; count = count+1)
			{
				sx = sx+SELECTED_CHART_DATA[0][count];
				sy = sy+SELECTED_CHART_DATA[1][count];
			}
			
			sxoss = sx/ss;
			
			fitB = 0;
			st2  = 0;
			
			sxx = 0;
			syy = 0;
			sxy = 0;
			ax  = sx/data_rows;
			ay  = sy/data_rows;
			
			for (count = 0; count<data_rows; count = count+1)
			{
				xt = SELECTED_CHART_DATA[0][count]-ax;
				yt = SELECTED_CHART_DATA[1][count]-ay;
				sxx = sxx+(xt)^2;
				syy = syy+(yt)^2;
				sxy = sxy+xt*yt;
				t = SELECTED_CHART_DATA[0][count]-sxoss;
				st2 = st2+t*t;
				fitB = fitB + t*SELECTED_CHART_DATA[1][count];
			}
			
			fitB = fitB/st2;
			fitA = (sy-sx*fitB)/ss;
			varA = Sqrt ((1+sx*sx/(ss*st2))/ss);
			varB = Sqrt (1/st2);
						
			fprintf (stdout, "\n\nCorrelation coefficient:",sxy/Sqrt(sxx*syy),"\n");
			fprintf (stdout, "\nLinear fit :\n\t y = ",fitA," + ", fitB, " * x\n");
			fprintf (stdout, "\nB = ",fitB, " +/- ", Sqrt (varB),"\nA = ",fitA, " +/- ", Sqrt (varA),"\n");
			return;
		}
	}
}

fprintf (stdout, "Please select two columns with independent values (1st column) and dependent values (2nd columns).\n");