vd_fun: ITR value estimated given a list of fitted model Calculate...
In sambiostat/WAPL: What the Package Does (One Line, Title Case)

ITR value estimated given a list of fitted model Calculate the value function given each lambda

1	vd_fun(outlist, lambda, x, y, A, foldid, group, loss)

`outlist:`	A list of fitted model, corresponding to lambda
`lambda:`	lambda vector chosen automatically when whole data if fitted
`x:`	feature matrix
`y:`	outcome/residual
`A:`	treatment observed
`foldid:`	length n vector of cv group index, for Cross validation purpose purpose
`group:`	group number, vector of length (2p+1), have to be consective, in each individual is one group then set group=seq(1: (2p+1))
`loss:`	default is "ls" for least square loss