estibeta: Estimates beta, knowing epsilon and delta.
In mvaldora/SPPS:

Estimates beta, knowing epsilon and delta.

1 2	estibeta(x, a, epsilon, delta, estim.method = "ML", phi = expit, dphi = dexpit, phiinv = expitinv, maxit = 3)

`x`	A matrix of covariates of dimension n x p
`a`	A vector a of 0s and 1s of dimension n
`epsilon`	A real number between 0 and 1 such that `epsilon`+`delta`<1
`delta`	A real number between 0 and 1
`estim.method`	The estimation method to be used for estimating the parameters "ML" (default) or "LS"
`phi`	A function that maps the real line onto the interval (0,1)
`dphi`	The derivative of `phi`
`phiinv`	The inverse of `phi`
`maxit`	The maximum number of iterations to be performed.