1) testgeomag.f
	To get one B=(Bx, By, Bz) in HV system for a given
	year and given place.
2) testgeomagMap.f
  	To get |B| as a function of logitude and  latitude all over
	the world.
	This can be plotted by gnuplot by
		splot "outputdata" w pm3d.
	To see projected map,
		set pm3d map
		splot "data" 
	To have different color assignment, use e.g,
		set palette rgbformulae 22,13,-31
	and use splot.
	To plot on the Mercator map, limit the latitude within
	(-80,80) (at most 85)  
	  say by awk '$2<80 && $2>-80 || NF==0' B1900.dat > B1900-b.dat
	and define 
	       my(x) = log( tan(pi/4.+ x*pi/180./2))
        in gnulot and use
	splot "outputdata" u 1:(mx($2)):3
	The inverse conversion is
	lat(y) =( 2*atan(exp(y))-pi/2 )*180/pi where y is Mercator value.

 Note:  Format with one blank line when changing x is essentail
	x1 y z
	x1 y z
	...
	x1 y z

	x2 y z
	x2 y z
	...
	x2 y z

	x3 y z
	x3 y z
	...
	x3 y z

