sub quant { # input: float 0 to 1 inclusive
	my $v = shift;
	if ($v<1/9) { return 0 }
	elsif ($v<2/9) { return 1 }
	elsif ($v<3/9) { return 2 }
	elsif ($v<4/9) { return 3 }
	elsif ($v<5/9) { return 4 }
	elsif ($v<6/9) { return 5 }
	elsif ($v<7/9) { return 6 }
	elsif ($v<8/9) { return 7 }
	else { return 8 }
}