@logl logf
c=(
	c(1)
	y^(
		c(1)-1
	)
	/
	(
		(
			c(2)^c(1)
		)
		(
			1+(y/c(2))^c(1)
		)^2
	)
	
sig2=c(3)

@param  c(1) 2
		c(2) 2
		c(3) 1
pi=3.14159
logf=(
	c(1)-1
)
log(y)
	+log(c(1))
	-c(1)
log(c(2))
	-(c(1)+2)
log(1+(y/c(2)))