estCt: estimate hypothesis c_st = c_t
In roualdes/spiders: Fits Predator Preferences Model

estimates parameters from hypothesis lambda_t = c_t * gamma_t

1	estCt(Xdst, Ydst, J, I, EM, em_maxiter, BALANCED)

`Xdst`	matrix of sums of number of eaten prey species s during occurrence t; rows indexed by time, and cols indexed by prey species, TxS
`Ydst`	matrix sum of number of caught prey species s during occurrence t; rows indexed by time, and cols indexed by prey species, TxS
`J`	vector of predators caught in each time period
`I`	vector of number of days all traps were left out in a given time period
`EM`	boolean; whether or not EM algorithm is used
`em_maxiter`	integer specifying max number of EM iterations
`BALANCED`	boolean; whether or not data are BALANCED