#  Data is weighted by sine squared inside a mute zone.
#  The weight is zero along the line	t =       x * slope0
#  It is bounded on the early side by	t = -tm + x * slopem
#  It is bounded on the late side by	t =  tp + x * slopep
#  Suggested defaults: slope0= 1./1.45; slopep= slope0; slopem=  0.; tp=tm =.150

subroutine mutter( tp,tm, slope0,slopep,slopem, d1,d2, o1,o2, data,n1,n2)
integer i1,i2,                                                     n1,n2
real t,x, wt, pih, tp,tm, slope0,slopep,slopem, d1,d2, o1,o2, data(n1,n2)
pih = 2. * atan(1.)			#  pi/2
do i2=1,n2 {	x= o2+(i2-1)*d2;	x = abs( x)
do i1=1,n1 {	t= o1+(i1-1)*d1;	wt = 1
	if( t > x*slope0 ) {
		if( t < tp + x * slopep)
			wt = sin( pih*(t-x*slope0)/(tp+x*(slopep-slope0))) ** 2
		}
	else 
		if( t > -tm + x * slopem)
			wt = sin( pih*(t-x*slope0)/(tm+x*(slope0-slopem))) ** 2
	data(i1,i2) = data(i1,i2) * wt
	}}
return; end